https://contractorsclassroom.com/ 2026-10-15 https://contractorsclassroom.com/courses 2026-10-15 https://contractorsclassroom.com/preview 2026-10-15 https://contractorsclassroom.com/pricing 2026-10-15 https://contractorsclassroom.com/videos 2026-10-15 https://contractorsclassroom.com/business-center 2026-10-15 https://contractorsclassroom.com/about 2026-10-15 https://contractorsclassroom.com/how-we-build-our-lessons 2026-10-15 https://contractorsclassroom.com/terms 2026-10-13 https://contractorsclassroom.com/privacy 2026-10-13 https://contractorsclassroom.com/refunds 2026-10-13 https://contractorsclassroom.com/spanish 2026-10-15 https://contractorsclassroom.com/spanish/courses 2026-10-15 https://contractorsclassroom.com/spanish/preview 2026-10-15 https://contractorsclassroom.com/spanish/pricing 2026-10-15 https://contractorsclassroom.com/spanish/videos 2026-10-15 https://contractorsclassroom.com/spanish/business-center 2026-10-15 https://contractorsclassroom.com/spanish/about 2026-10-15 https://contractorsclassroom.com/spanish/how-we-build-our-lessons 2026-10-15 https://contractorsclassroom.com/spanish/terms 2026-10-13 https://contractorsclassroom.com/spanish/privacy 2026-10-13 https://contractorsclassroom.com/spanish/refunds 2026-10-13 https://contractorsclassroom.com/programs/california-contractor-law-and-business-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/lb/en/hero-1600.jpg Law and Business Exam Prep for California Contractors https://contractorsclassroom.com/landing-images/lb-choosing-a-business-entity/en/thumb-400.jpg Choosing a Business Entity: Liability, Taxes, and What Happens to the License - lesson diagram https://contractorsclassroom.com/landing-images/lb-qualifying-individual-rmo-rme/en/thumb-400.jpg The Qualifying Individual: RMO, RME, and the 90-Day Replacement Clock - lesson diagram https://contractorsclassroom.com/landing-images/lb-bonds-insurance-workers-comp/en/thumb-400.jpg Bonds, Liability Insurance, and Workers’ Comp: What the License Requires on File - lesson diagram https://contractorsclassroom.com/landing-images/lb-home-improvement-contract-checklist/en/thumb-400.jpg The Home Improvement Contract Checklist: Down Payment, Change Orders, and Right to Cancel - lesson diagram https://contractorsclassroom.com/landing-images/lb-preliminary-notice-and-lien-calendar/en/thumb-400.jpg The Preliminary Notice and Mechanics Lien Calendar - lesson diagram https://contractorsclassroom.com/landing-images/lb-first-employee-abc-test-payroll/en/thumb-400.jpg Your First Employee: the ABC Test, Payroll Taxes, and Deposit Deadlines - lesson diagram https://contractorsclassroom.com/spanish/programs/examen-ley-y-negocios-licencia-contratista-california 2026-10-14 https://contractorsclassroom.com/landing-images/lb/es/hero-1600.jpg Preparación del examen de Ley y Negocios para contratistas de California https://contractorsclassroom.com/landing-images/lb-choosing-a-business-entity/en/thumb-400.jpg Choosing a Business Entity: Liability, Taxes, and What Happens to the License - lesson diagram https://contractorsclassroom.com/landing-images/lb-qualifying-individual-rmo-rme/en/thumb-400.jpg The Qualifying Individual: RMO, RME, and the 90-Day Replacement Clock - lesson diagram https://contractorsclassroom.com/landing-images/lb-bonds-insurance-workers-comp/en/thumb-400.jpg Bonds, Liability Insurance, and Workers’ Comp: What the License Requires on File - lesson diagram https://contractorsclassroom.com/landing-images/lb-home-improvement-contract-checklist/en/thumb-400.jpg The Home Improvement Contract Checklist: Down Payment, Change Orders, and Right to Cancel - lesson diagram https://contractorsclassroom.com/landing-images/lb-preliminary-notice-and-lien-calendar/en/thumb-400.jpg The Preliminary Notice and Mechanics Lien Calendar - lesson diagram https://contractorsclassroom.com/landing-images/lb-first-employee-abc-test-payroll/en/thumb-400.jpg Your First Employee: the ABC Test, Payroll Taxes, and Deposit Deadlines - lesson diagram https://contractorsclassroom.com/trades/a-general-engineering-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/a/en/hero-1600.jpg General Engineering Contractor License Exam Prep (A) https://contractorsclassroom.com/spanish/trades/a-licencia-contratista-ingenieria-general-examen 2026-10-14 https://contractorsclassroom.com/landing-images/a/es/hero-1600.jpg Preparación para el examen de licencia de contratista de ingeniería general (A) https://contractorsclassroom.com/trades/asb-asbestos-certification-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/asb/en/hero-1600.jpg Asbestos Certification Exam Prep (ASB) https://contractorsclassroom.com/landing-images/asb-certification-and-registration-100-sq-ft/en/thumb-400.jpg Who Needs the ASB Certification and DOSH Registration: The 100 Square Foot Line - lesson diagram https://contractorsclassroom.com/landing-images/asb-exposure-assessment-and-monitoring/en/thumb-400.jpg Exposure Assessment and Monitoring: PELs, the Initial Assessment, and the Negative Exposure Assessment - lesson diagram https://contractorsclassroom.com/landing-images/asb-class-i-iv-work-training-and-competent-person/en/thumb-400.jpg Class I to IV Asbestos Work, Training Hours, and the Competent Person - lesson diagram https://contractorsclassroom.com/landing-images/asb-medical-surveillance-and-recordkeeping/en/thumb-400.jpg Medical Surveillance and Recordkeeping: The 30-Day Trigger and How Long to Keep Records - lesson diagram https://contractorsclassroom.com/landing-images/asb-consultants-and-site-surveillance-technicians/en/thumb-400.jpg Asbestos Consultants and Site Surveillance Technicians: What a Contractor May and May Not Do - lesson diagram https://contractorsclassroom.com/landing-images/asb-finding-acm-pacm-presumption-and-building-survey/en/thumb-400.jpg Finding the ACM: the PACM Presumption, the Building Survey, and Sampling Counts - lesson diagram https://contractorsclassroom.com/spanish/trades/asb-certificacion-asbesto-examen 2026-10-14 https://contractorsclassroom.com/landing-images/asb/es/hero-1600.jpg Preparación para el examen de certificación de asbesto (ASB) https://contractorsclassroom.com/landing-images/asb-certification-and-registration-100-sq-ft/en/thumb-400.jpg Who Needs the ASB Certification and DOSH Registration: The 100 Square Foot Line - lesson diagram https://contractorsclassroom.com/landing-images/asb-exposure-assessment-and-monitoring/en/thumb-400.jpg Exposure Assessment and Monitoring: PELs, the Initial Assessment, and the Negative Exposure Assessment - lesson diagram https://contractorsclassroom.com/landing-images/asb-class-i-iv-work-training-and-competent-person/en/thumb-400.jpg Class I to IV Asbestos Work, Training Hours, and the Competent Person - lesson diagram https://contractorsclassroom.com/landing-images/asb-medical-surveillance-and-recordkeeping/en/thumb-400.jpg Medical Surveillance and Recordkeeping: The 30-Day Trigger and How Long to Keep Records - lesson diagram https://contractorsclassroom.com/landing-images/asb-consultants-and-site-surveillance-technicians/en/thumb-400.jpg Asbestos Consultants and Site Surveillance Technicians: What a Contractor May and May Not Do - lesson diagram https://contractorsclassroom.com/landing-images/asb-finding-acm-pacm-presumption-and-building-survey/en/thumb-400.jpg Finding the ACM: the PACM Presumption, the Building Survey, and Sampling Counts - lesson diagram https://contractorsclassroom.com/trades/b-general-building-contractor-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/b/en/hero-1600.jpg General Building Contractor License Exam Prep (B) https://contractorsclassroom.com/spanish/trades/b-licencia-contratista-general-construccion-examen 2026-10-14 https://contractorsclassroom.com/landing-images/b/es/hero-1600.jpg Preparación para el examen de licencia de contratista general de edificios (B) https://contractorsclassroom.com/trades/b2-residential-remodeling-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/b2/en/hero-1600.jpg Residential Remodeling Contractor License Exam Prep (B-2) https://contractorsclassroom.com/landing-images/b2-basement-egress-window-well/en/thumb-400.jpg Basement Egress Window Wells: Size, Depth, and Ladder - lesson diagram https://contractorsclassroom.com/landing-images/b2-attic-conversion-sloped-ceiling-area/en/thumb-400.jpg Attic Conversions: Counting Floor Area Under a Sloped Ceiling - lesson diagram https://contractorsclassroom.com/landing-images/b2-remodel-smoke-co-alarm-count/en/thumb-400.jpg Smoke and CO Alarm Upgrades Triggered by a Remodel - lesson diagram https://contractorsclassroom.com/landing-images/b2-lead-safe-6-20-square-foot-test/en/thumb-400.jpg Lead-Safe Remodeling: The 6 and 20 Square-Foot Test - lesson diagram https://contractorsclassroom.com/landing-images/b2-bearing-wall-removal-beam-bearing/en/thumb-400.jpg Removing a Bearing Wall: Sizing the Replacement Girder From CRC Table R602.7(2) - lesson diagram https://contractorsclassroom.com/spanish/trades/b2-licencia-contratista-remodelacion-residencial-examen 2026-10-14 https://contractorsclassroom.com/landing-images/b2/es/hero-1600.jpg Preparación para el examen de licencia de contratista de remodelación residencial (B-2) https://contractorsclassroom.com/landing-images/b2-basement-egress-window-well/en/thumb-400.jpg Basement Egress Window Wells: Size, Depth, and Ladder - lesson diagram https://contractorsclassroom.com/landing-images/b2-attic-conversion-sloped-ceiling-area/en/thumb-400.jpg Attic Conversions: Counting Floor Area Under a Sloped Ceiling - lesson diagram https://contractorsclassroom.com/landing-images/b2-remodel-smoke-co-alarm-count/en/thumb-400.jpg Smoke and CO Alarm Upgrades Triggered by a Remodel - lesson diagram https://contractorsclassroom.com/landing-images/b2-lead-safe-6-20-square-foot-test/en/thumb-400.jpg Lead-Safe Remodeling: The 6 and 20 Square-Foot Test - lesson diagram https://contractorsclassroom.com/landing-images/b2-bearing-wall-removal-beam-bearing/en/thumb-400.jpg Removing a Bearing Wall: Sizing the Replacement Girder From CRC Table R602.7(2) - lesson diagram https://contractorsclassroom.com/trades/c2-insulation-acoustical-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c02/en/hero-1600.jpg Insulation and Acoustical Contractor License Exam Prep (C-2) https://contractorsclassroom.com/landing-images/c02-suspended-grid-takeoff/en/thumb-400.jpg Suspended Ceiling Grid Takeoff (2x4 Lay-In) - lesson diagram https://contractorsclassroom.com/landing-images/c02-ceiling-seismic-bracing-layout/en/thumb-400.jpg Seismic Bracing Rules for Suspended Ceilings - lesson diagram https://contractorsclassroom.com/landing-images/c02-blown-attic-bag-count/en/thumb-400.jpg Blown-In Attic Insulation: R-Value, Weight and Bag Count - lesson diagram https://contractorsclassroom.com/landing-images/c02-spray-foam-board-feet/en/thumb-400.jpg Spray Foam: Board Feet, Thickness and Lifts - lesson diagram https://contractorsclassroom.com/landing-images/c02-composite-stc-gaps/en/thumb-400.jpg Composite STC: What a Gap Does to a Sound-Rated Wall - lesson diagram https://contractorsclassroom.com/spanish/trades/c2-licencia-contratista-aislamiento-acustica-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c02/es/hero-1600.jpg Preparación para el examen de licencia de contratista de aislamiento y acústica (C-2) https://contractorsclassroom.com/landing-images/c02-suspended-grid-takeoff/en/thumb-400.jpg Suspended Ceiling Grid Takeoff (2x4 Lay-In) - lesson diagram https://contractorsclassroom.com/landing-images/c02-ceiling-seismic-bracing-layout/en/thumb-400.jpg Seismic Bracing Rules for Suspended Ceilings - lesson diagram https://contractorsclassroom.com/landing-images/c02-blown-attic-bag-count/en/thumb-400.jpg Blown-In Attic Insulation: R-Value, Weight and Bag Count - lesson diagram https://contractorsclassroom.com/landing-images/c02-spray-foam-board-feet/en/thumb-400.jpg Spray Foam: Board Feet, Thickness and Lifts - lesson diagram https://contractorsclassroom.com/landing-images/c02-composite-stc-gaps/en/thumb-400.jpg Composite STC: What a Gap Does to a Sound-Rated Wall - lesson diagram https://contractorsclassroom.com/trades/c4-boiler-steam-fitting-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c04/en/hero-1600.jpg Boiler and Steam Fitting Contractor License Exam Prep (C-4) https://contractorsclassroom.com/landing-images/c04-expansion-tank-sizing/en/thumb-400.jpg Sizing a Closed Expansion Tank by CMC Section 1004.4 - lesson diagram https://contractorsclassroom.com/landing-images/c04-boiler-control-groups/en/thumb-400.jpg Boiler Group and Required Controls (CMC Table 1003.2.1) - lesson diagram https://contractorsclassroom.com/landing-images/c04-boiler-room-combustion-air/en/thumb-400.jpg Combustion Air for a Boiler Room (CMC Chapter 7) - lesson diagram https://contractorsclassroom.com/landing-images/c04-hydronic-test-relief-discharge/en/thumb-400.jpg Hydronic Test Pressure and Relief Valve Discharge (CMC 1205.2, 1206.2) - lesson diagram https://contractorsclassroom.com/landing-images/c04-pipe-insulation-table-120-3/en/thumb-400.jpg Hydronic and Steam Pipe Insulation (Energy Code Table 120.3-A-1) - lesson diagram https://contractorsclassroom.com/landing-images/c04-boiler-energy-code-return-water/en/thumb-400.jpg Boiler Energy Code Rules: Input Size and Return Water Temperature - lesson diagram https://contractorsclassroom.com/spanish/trades/c4-licencia-contratista-calderas-vapor-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c04/es/hero-1600.jpg Preparación para el examen de licencia de contratista de calderas y vapor (C-4) https://contractorsclassroom.com/landing-images/c04-expansion-tank-sizing/en/thumb-400.jpg Sizing a Closed Expansion Tank by CMC Section 1004.4 - lesson diagram https://contractorsclassroom.com/landing-images/c04-boiler-control-groups/en/thumb-400.jpg Boiler Group and Required Controls (CMC Table 1003.2.1) - lesson diagram https://contractorsclassroom.com/landing-images/c04-boiler-room-combustion-air/en/thumb-400.jpg Combustion Air for a Boiler Room (CMC Chapter 7) - lesson diagram https://contractorsclassroom.com/landing-images/c04-hydronic-test-relief-discharge/en/thumb-400.jpg Hydronic Test Pressure and Relief Valve Discharge (CMC 1205.2, 1206.2) - lesson diagram https://contractorsclassroom.com/landing-images/c04-pipe-insulation-table-120-3/en/thumb-400.jpg Hydronic and Steam Pipe Insulation (Energy Code Table 120.3-A-1) - lesson diagram https://contractorsclassroom.com/landing-images/c04-boiler-energy-code-return-water/en/thumb-400.jpg Boiler Energy Code Rules: Input Size and Return Water Temperature - lesson diagram https://contractorsclassroom.com/trades/c5-framing-carpentry-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c05/en/hero-1600.jpg Framing and Rough Carpentry Contractor License Exam Prep (C-5) https://contractorsclassroom.com/landing-images/c05-notching-boring-limits/en/thumb-400.jpg Notching and Boring Limits for Joists, Rafters, and Studs - lesson diagram https://contractorsclassroom.com/landing-images/c05-joist-deflection-check/en/thumb-400.jpg Floor Joist Deflection: The L/360 Limit and the Span Table - lesson diagram https://contractorsclassroom.com/landing-images/c05-sill-plate-anchor-bolts/en/thumb-400.jpg Sill Plate Anchor Bolts: Spacing, End Distance, and Counting - lesson diagram https://contractorsclassroom.com/landing-images/c05-deck-ledger-fastening/en/thumb-400.jpg Deck Ledger Fastening: Lag Screw Spacing and Lateral Ties - lesson diagram https://contractorsclassroom.com/landing-images/c05-shear-wall-nail-count/en/thumb-400.jpg Shear Wall Fastening: Edge and Field Spacing, Fastener Counts, and 3x Framing - lesson diagram https://contractorsclassroom.com/spanish/trades/c5-licencia-contratista-armazon-carpinteria-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c05/es/hero-1600.jpg Preparación para el examen de licencia de contratista de armazón y carpintería en bruto (C-5) https://contractorsclassroom.com/landing-images/c05-notching-boring-limits/en/thumb-400.jpg Notching and Boring Limits for Joists, Rafters, and Studs - lesson diagram https://contractorsclassroom.com/landing-images/c05-joist-deflection-check/en/thumb-400.jpg Floor Joist Deflection: The L/360 Limit and the Span Table - lesson diagram https://contractorsclassroom.com/landing-images/c05-sill-plate-anchor-bolts/en/thumb-400.jpg Sill Plate Anchor Bolts: Spacing, End Distance, and Counting - lesson diagram https://contractorsclassroom.com/landing-images/c05-deck-ledger-fastening/en/thumb-400.jpg Deck Ledger Fastening: Lag Screw Spacing and Lateral Ties - lesson diagram https://contractorsclassroom.com/landing-images/c05-shear-wall-nail-count/en/thumb-400.jpg Shear Wall Fastening: Edge and Field Spacing, Fastener Counts, and 3x Framing - lesson diagram https://contractorsclassroom.com/trades/c6-cabinet-finish-carpentry-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c06/en/hero-1600.jpg Cabinet and Finish Carpentry Contractor License Exam Prep (C-6) https://contractorsclassroom.com/landing-images/c06-crown-molding-compound-miters/en/thumb-400.jpg Crown Molding: Spring Angle and Compound Miter Settings - lesson diagram https://contractorsclassroom.com/landing-images/c06-stair-riser-tread-layout/en/thumb-400.jpg Stair Layout: Rise, Run, and Baluster Spacing - lesson diagram https://contractorsclassroom.com/landing-images/c06-prehung-door-opening-and-clearance/en/thumb-400.jpg Doors: Clear Width, Clear Height, and Hardware Checks - lesson diagram https://contractorsclassroom.com/landing-images/c06-accessible-sink-base-clearances/en/thumb-400.jpg Accessible Sink Cabinets: Counter Height and Knee Clearance - lesson diagram https://contractorsclassroom.com/landing-images/c06-accessible-kitchen-clearances/en/thumb-400.jpg Accessible Kitchens: Aisle Clearances and Work Surface - lesson diagram https://contractorsclassroom.com/landing-images/c06-composite-wood-formaldehyde-and-voc-limits/en/thumb-400.jpg Cabinet Materials: Formaldehyde and VOC Limits - lesson diagram https://contractorsclassroom.com/spanish/trades/c6-licencia-contratista-gabinetes-carpinteria-acabado-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c06/es/hero-1600.jpg Preparación para el examen de licencia de contratista de gabinetes y carpintería de acabado (C-6) https://contractorsclassroom.com/landing-images/c06-crown-molding-compound-miters/en/thumb-400.jpg Crown Molding: Spring Angle and Compound Miter Settings - lesson diagram https://contractorsclassroom.com/landing-images/c06-stair-riser-tread-layout/en/thumb-400.jpg Stair Layout: Rise, Run, and Baluster Spacing - lesson diagram https://contractorsclassroom.com/landing-images/c06-prehung-door-opening-and-clearance/en/thumb-400.jpg Doors: Clear Width, Clear Height, and Hardware Checks - lesson diagram https://contractorsclassroom.com/landing-images/c06-accessible-sink-base-clearances/en/thumb-400.jpg Accessible Sink Cabinets: Counter Height and Knee Clearance - lesson diagram https://contractorsclassroom.com/landing-images/c06-accessible-kitchen-clearances/en/thumb-400.jpg Accessible Kitchens: Aisle Clearances and Work Surface - lesson diagram https://contractorsclassroom.com/landing-images/c06-composite-wood-formaldehyde-and-voc-limits/en/thumb-400.jpg Cabinet Materials: Formaldehyde and VOC Limits - lesson diagram https://contractorsclassroom.com/trades/c7-low-voltage-systems-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c07/en/hero-1600.jpg Low Voltage Systems Contractor License Exam Prep (C-7) https://contractorsclassroom.com/landing-images/c07-low-voltage-dc-voltage-drop/en/thumb-400.jpg Voltage Drop on Low-Voltage DC Runs (Locks, Cameras, Sounders) - lesson diagram https://contractorsclassroom.com/landing-images/c07-class2-power-source-limits/en/thumb-400.jpg Class 2 Power Source Limits: How Big a Supply Can One Circuit Use - lesson diagram https://contractorsclassroom.com/landing-images/c07-circuit-separation-rules/en/thumb-400.jpg Keeping Low-Voltage, Fire Alarm and Communications Wiring Apart - lesson diagram https://contractorsclassroom.com/landing-images/c07-fire-alarm-cfc-907-numbers/en/thumb-400.jpg Fire Alarm Layout Numbers Printed in CFC Section 907 - lesson diagram https://contractorsclassroom.com/spanish/trades/c7-licencia-contratista-bajo-voltaje-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c07/es/hero-1600.jpg Preparación para el examen de licencia de contratista de sistemas de bajo voltaje (C-7) https://contractorsclassroom.com/landing-images/c07-low-voltage-dc-voltage-drop/en/thumb-400.jpg Voltage Drop on Low-Voltage DC Runs (Locks, Cameras, Sounders) - lesson diagram https://contractorsclassroom.com/landing-images/c07-class2-power-source-limits/en/thumb-400.jpg Class 2 Power Source Limits: How Big a Supply Can One Circuit Use - lesson diagram https://contractorsclassroom.com/landing-images/c07-circuit-separation-rules/en/thumb-400.jpg Keeping Low-Voltage, Fire Alarm and Communications Wiring Apart - lesson diagram https://contractorsclassroom.com/landing-images/c07-fire-alarm-cfc-907-numbers/en/thumb-400.jpg Fire Alarm Layout Numbers Printed in CFC Section 907 - lesson diagram https://contractorsclassroom.com/trades/c8-concrete-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c08/en/hero-1600.jpg Concrete Contractor License Exam Prep (C-8) https://contractorsclassroom.com/landing-images/reading-a-rebar-callout/en/thumb-400.jpg Reading a Rebar Callout - lesson diagram https://contractorsclassroom.com/landing-images/c08-footing-size-tables/en/thumb-400.jpg Sizing a Footing from the CRC Tables - lesson diagram https://contractorsclassroom.com/landing-images/c08-strength-weathering-air/en/thumb-400.jpg Specified Strength and Air Entrainment by Exposure - lesson diagram https://contractorsclassroom.com/landing-images/c08-slab-on-ground-requirements/en/thumb-400.jpg Slab-on-Ground: Thickness, Base, Vapor Retarder and Capillary Break - lesson diagram https://contractorsclassroom.com/landing-images/c08-concrete-special-inspection/en/thumb-400.jpg When Concrete Work Needs Special Inspection (CBC Table 1705.3) - lesson diagram https://contractorsclassroom.com/landing-images/c08-caltrans-slump-water-delivery/en/thumb-400.jpg Caltrans Concrete: Slump Limits, Free Water and Delivery Time - lesson diagram https://contractorsclassroom.com/spanish/trades/c8-licencia-contratista-concreto-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c08/es/hero-1600.jpg Preparación para el examen de licencia de contratista de concreto (C-8) https://contractorsclassroom.com/landing-images/reading-a-rebar-callout/en/thumb-400.jpg Reading a Rebar Callout - lesson diagram https://contractorsclassroom.com/landing-images/c08-footing-size-tables/en/thumb-400.jpg Sizing a Footing from the CRC Tables - lesson diagram https://contractorsclassroom.com/landing-images/c08-strength-weathering-air/en/thumb-400.jpg Specified Strength and Air Entrainment by Exposure - lesson diagram https://contractorsclassroom.com/landing-images/c08-slab-on-ground-requirements/en/thumb-400.jpg Slab-on-Ground: Thickness, Base, Vapor Retarder and Capillary Break - lesson diagram https://contractorsclassroom.com/landing-images/c08-concrete-special-inspection/en/thumb-400.jpg When Concrete Work Needs Special Inspection (CBC Table 1705.3) - lesson diagram https://contractorsclassroom.com/landing-images/c08-caltrans-slump-water-delivery/en/thumb-400.jpg Caltrans Concrete: Slump Limits, Free Water and Delivery Time - lesson diagram https://contractorsclassroom.com/trades/c9-drywall-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c09/en/hero-1600.jpg Drywall Contractor License Exam Prep (C-9) https://contractorsclassroom.com/landing-images/c09-steel-framing-thickness-screws/en/thumb-400.jpg Steel Framing Thickness and Screw Selection for Board - lesson diagram https://contractorsclassroom.com/landing-images/c09-fastener-spacing-screw-count/en/thumb-400.jpg Screw Spacing and Screw Count per Sheet - lesson diagram https://contractorsclassroom.com/landing-images/c09-fire-rated-wall-layers-takeoff/en/thumb-400.jpg Fire-Rated Partitions: Layers, Offset Joints, and Board Takeoff - lesson diagram https://contractorsclassroom.com/landing-images/c09-rated-wall-boxes-signs/en/thumb-400.jpg Rated Walls: Box Openings and Concealed-Space Signs - lesson diagram https://contractorsclassroom.com/landing-images/c09-diaphragm-ceiling-fasteners/en/thumb-400.jpg Gypsum Board Diaphragm Ceilings: Nails, Spacing, and Capacity - lesson diagram https://contractorsclassroom.com/spanish/trades/c9-licencia-contratista-paneles-de-yeso-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c09/es/hero-1600.jpg Preparación para el examen de licencia de contratista de paneles de yeso (C-9) https://contractorsclassroom.com/landing-images/c09-steel-framing-thickness-screws/en/thumb-400.jpg Steel Framing Thickness and Screw Selection for Board - lesson diagram https://contractorsclassroom.com/landing-images/c09-fastener-spacing-screw-count/en/thumb-400.jpg Screw Spacing and Screw Count per Sheet - lesson diagram https://contractorsclassroom.com/landing-images/c09-fire-rated-wall-layers-takeoff/en/thumb-400.jpg Fire-Rated Partitions: Layers, Offset Joints, and Board Takeoff - lesson diagram https://contractorsclassroom.com/landing-images/c09-rated-wall-boxes-signs/en/thumb-400.jpg Rated Walls: Box Openings and Concealed-Space Signs - lesson diagram https://contractorsclassroom.com/landing-images/c09-diaphragm-ceiling-fasteners/en/thumb-400.jpg Gypsum Board Diaphragm Ceilings: Nails, Spacing, and Capacity - lesson diagram https://contractorsclassroom.com/trades/c10-electrical-contractor-electrician-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c10/en/hero-1600.jpg Electrical Contractor License Exam Prep (C-10) https://contractorsclassroom.com/landing-images/c10-lockout-tagout-energized-work/en/thumb-400.jpg Lockout/Tagout and Working on Energized Equipment - lesson diagram https://contractorsclassroom.com/landing-images/c10-temporary-power-gfci-aegcp/en/thumb-400.jpg Temporary Power: GFCIs and the Assured Grounding Program - 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lesson diagram https://contractorsclassroom.com/landing-images/c11-accessible-car-door-timing/en/thumb-400.jpg Accessible Car Size and Door Timing - lesson diagram https://contractorsclassroom.com/landing-images/c11-hoistway-fire-rating/en/thumb-400.jpg Hoistway Fire Rating and Machine Room Enclosure - lesson diagram https://contractorsclassroom.com/landing-images/c11-cab-lighting-fan-energy/en/thumb-400.jpg Elevator Cab Lighting and Fan Energy Limits - lesson diagram https://contractorsclassroom.com/spanish/trades/c11-licencia-contratista-ascensores-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c11/es/hero-1600.jpg Preparación para el examen de licencia de contratista de ascensores (C-11) https://contractorsclassroom.com/landing-images/c11-hoistway-vent-area/en/thumb-400.jpg Hoistway Vent Area and Operation - lesson diagram https://contractorsclassroom.com/landing-images/c11-accessible-car-door-timing/en/thumb-400.jpg Accessible Car Size and Door Timing - lesson diagram https://contractorsclassroom.com/landing-images/c11-hoistway-fire-rating/en/thumb-400.jpg Hoistway Fire Rating and Machine Room Enclosure - 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lesson diagram https://contractorsclassroom.com/landing-images/c12-paver-speed-truck-scheduling/en/thumb-400.jpg Matching Paver Speed to Plant Output and Truck Count - lesson diagram https://contractorsclassroom.com/landing-images/c12-tack-coat-spray-rates/en/thumb-400.jpg Tack Coat: Residual Rate, Spray Rate, and Dilution - lesson diagram https://contractorsclassroom.com/spanish/trades/c12-licencia-contratista-movimiento-tierras-pavimentacion-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c12/es/hero-1600.jpg Preparación para el examen de licencia de contratista de movimiento de tierras y pavimentación (C-12) https://contractorsclassroom.com/landing-images/c12-hma-tonnage-spread-rate/en/thumb-400.jpg Hot Mix Asphalt Tonnage and the Spread-Rate Check - lesson diagram https://contractorsclassroom.com/landing-images/c12-relative-compaction-field-test/en/thumb-400.jpg Relative Compaction: Reading a Nuclear-Gauge Density Test - lesson diagram https://contractorsclassroom.com/landing-images/c12-cut-fill-swell-shrink/en/thumb-400.jpg Balancing Cut and Fill: Bank, Loose, and Compacted Yards - 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lesson diagram https://contractorsclassroom.com/landing-images/c15-subfloor-underlayment-crc-r503/en/thumb-400.jpg Subfloor Panels and Underlayment: Spans, Edge Support, and Particleboard - lesson diagram https://contractorsclassroom.com/landing-images/c15-silica-floor-grinding-8ccr-1532-3/en/thumb-400.jpg Dust Control When Grinding Floors: 8 CCR 1532.3 Table 1 - lesson diagram https://contractorsclassroom.com/landing-images/c15-calgreen-flooring-adhesive-voc-80-percent/en/thumb-400.jpg CALGreen Flooring Products: Adhesive VOC Limits and the 80% Rule - lesson diagram https://contractorsclassroom.com/landing-images/c15-floor-finish-fire-class-cbc-804/en/thumb-400.jpg Floor Finish Fire Class: Radiant Flux Classes and Where They Apply - lesson diagram https://contractorsclassroom.com/landing-images/c15-floor-transitions-changes-in-level/en/thumb-400.jpg Floor Transitions: Changes in Level, Thresholds, and Carpet Edges - lesson diagram https://contractorsclassroom.com/spanish/trades/c15-licencia-contratista-pisos-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c15/es/hero-1600.jpg Preparación para el examen de licencia de contratista de pisos (C-15) https://contractorsclassroom.com/landing-images/c15-slab-vapor-retarder-capillary-break/en/thumb-400.jpg Slab Moisture: Vapor Retarder and Capillary Break Under the Slab - lesson diagram https://contractorsclassroom.com/landing-images/c15-subfloor-underlayment-crc-r503/en/thumb-400.jpg Subfloor Panels and Underlayment: Spans, Edge Support, and Particleboard - lesson diagram https://contractorsclassroom.com/landing-images/c15-silica-floor-grinding-8ccr-1532-3/en/thumb-400.jpg Dust Control When Grinding Floors: 8 CCR 1532.3 Table 1 - lesson diagram https://contractorsclassroom.com/landing-images/c15-calgreen-flooring-adhesive-voc-80-percent/en/thumb-400.jpg CALGreen Flooring Products: Adhesive VOC Limits and the 80% Rule - lesson diagram https://contractorsclassroom.com/landing-images/c15-floor-finish-fire-class-cbc-804/en/thumb-400.jpg Floor Finish Fire Class: Radiant Flux Classes and Where They Apply - lesson diagram https://contractorsclassroom.com/landing-images/c15-floor-transitions-changes-in-level/en/thumb-400.jpg Floor Transitions: Changes in Level, Thresholds, and Carpet Edges - lesson diagram https://contractorsclassroom.com/trades/c16-fire-protection-sprinkler-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c16/en/hero-1600.jpg Fire Protection Contractor License Exam Prep (C-16) https://contractorsclassroom.com/landing-images/c16-sprinkler-required-triggers/en/thumb-400.jpg Where Sprinklers Are Required: CFC 903.2 Triggers - 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lesson diagram https://contractorsclassroom.com/landing-images/c17-sloped-glazing-load-combinations/en/thumb-400.jpg Sloped Glazing and Skylights: Load Combinations - lesson diagram https://contractorsclassroom.com/landing-images/c17-wind-load-check-glass-framing/en/thumb-400.jpg Wind Load Check and Glass Framing Deflection Limits - lesson diagram https://contractorsclassroom.com/landing-images/c17-glass-guards-and-handrails/en/thumb-400.jpg Glass Guards and Handrails - lesson diagram https://contractorsclassroom.com/landing-images/c17-storefront-energy-area-weighted/en/thumb-400.jpg Storefront Energy Compliance: Area-Weighted Ratings - lesson diagram https://contractorsclassroom.com/spanish/trades/c17-licencia-contratista-vidrieria-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c17/es/hero-1600.jpg Preparación para el examen de licencia de contratista de vidriería (C-17) https://contractorsclassroom.com/landing-images/c17-safety-glazing-hazardous-locations/en/thumb-400.jpg Safety Glazing: Is This Pane a Hazardous Location? - lesson diagram https://contractorsclassroom.com/landing-images/c17-sloped-glazing-load-combinations/en/thumb-400.jpg Sloped Glazing and Skylights: Load Combinations - lesson diagram https://contractorsclassroom.com/landing-images/c17-wind-load-check-glass-framing/en/thumb-400.jpg Wind Load Check and Glass Framing Deflection Limits - lesson diagram https://contractorsclassroom.com/landing-images/c17-glass-guards-and-handrails/en/thumb-400.jpg Glass Guards and Handrails - lesson diagram https://contractorsclassroom.com/landing-images/c17-storefront-energy-area-weighted/en/thumb-400.jpg Storefront Energy Compliance: Area-Weighted Ratings - lesson diagram https://contractorsclassroom.com/trades/c20-hvac-heating-air-conditioning-contractor-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c20/en/hero-1600.jpg HVAC Contractor License Exam Prep (C-20) https://contractorsclassroom.com/landing-images/c20-airflow-fan-efficacy/en/thumb-400.jpg Airflow per Ton and Fan Efficacy: The Title 24 Verification Numbers - 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lesson diagram https://contractorsclassroom.com/landing-images/c21-jacks-cribbing-bearing/en/thumb-400.jpg Jacks, Cribbing, and Ground Bearing Under a Lifted House - lesson diagram https://contractorsclassroom.com/landing-images/c21-house-move-height-width-clearance/en/thumb-400.jpg House Moves: Height, Width, and Route Clearance - lesson diagram https://contractorsclassroom.com/landing-images/c21-demolition-survey-sequence-openings/en/thumb-400.jpg Demolition Order of Work: Survey, Utilities, Sequence, and the 25 Percent Rule - lesson diagram https://contractorsclassroom.com/landing-images/c21-pedestrian-protection-drop-zones/en/thumb-400.jpg Protecting the Public and Workers Below: Table 3306.1, Canopies, and Drop Zones - lesson diagram https://contractorsclassroom.com/landing-images/c21-debris-weight-diversion-loads/en/thumb-400.jpg Demolition Debris: Tons, the 65 Percent Diversion Rule, and Truckloads - lesson diagram https://contractorsclassroom.com/trades/c22-asbestos-abatement-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c22/en/hero-1600.jpg Asbestos Abatement Contractor License Exam Prep (C-22) https://contractorsclassroom.com/landing-images/c22-negative-air-unit-sizing/en/thumb-400.jpg Sizing Negative Air Units: Enclosure Volume, ACH, and CFM - lesson diagram https://contractorsclassroom.com/landing-images/c22-pcm-air-sample-fiber-count/en/thumb-400.jpg Air Sampling Math: Turning a PCM Fiber Count Into Fibers per cc - lesson diagram https://contractorsclassroom.com/landing-images/c22-respirator-selection-apf-muc/en/thumb-400.jpg Respirator Selection: Class of Work, Exposure Level, and Maximum Use Concentration - lesson diagram https://contractorsclassroom.com/landing-images/c22-regulated-area-barriers-decon/en/thumb-400.jpg Regulated Area Set-Up: Barriers, Signs, and the 25 Linear / 10 Square Foot Decon Trigger - lesson diagram https://contractorsclassroom.com/landing-images/c22-glovebag-removal-and-waste-bagging/en/thumb-400.jpg Glovebag Removal on Pipe Insulation and Bagging the Waste - lesson diagram https://contractorsclassroom.com/spanish/trades/c22-licencia-contratista-reduccion-asbesto-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c22/es/hero-1600.jpg Preparación para el examen de licencia de contratista de reducción de asbesto (C-22) https://contractorsclassroom.com/landing-images/c22-negative-air-unit-sizing/en/thumb-400.jpg Sizing Negative Air Units: Enclosure Volume, ACH, and CFM - lesson diagram https://contractorsclassroom.com/landing-images/c22-pcm-air-sample-fiber-count/en/thumb-400.jpg Air Sampling Math: Turning a PCM Fiber Count Into Fibers per cc - lesson diagram https://contractorsclassroom.com/landing-images/c22-respirator-selection-apf-muc/en/thumb-400.jpg Respirator Selection: Class of Work, Exposure Level, and Maximum Use Concentration - lesson diagram https://contractorsclassroom.com/landing-images/c22-regulated-area-barriers-decon/en/thumb-400.jpg Regulated Area Set-Up: Barriers, Signs, and the 25 Linear / 10 Square Foot Decon Trigger - lesson diagram https://contractorsclassroom.com/landing-images/c22-glovebag-removal-and-waste-bagging/en/thumb-400.jpg Glovebag Removal on Pipe Insulation and Bagging the Waste - lesson diagram https://contractorsclassroom.com/trades/c23-ornamental-metal-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c23/en/hero-1600.jpg Ornamental Metal Contractor License Exam Prep (C-23) https://contractorsclassroom.com/landing-images/c23-stair-stringer-layout/en/thumb-400.jpg Stair Stringer Layout: Riser Count, Tread Run, and Uniformity - lesson diagram https://contractorsclassroom.com/landing-images/c23-guard-baluster-spacing/en/thumb-400.jpg Guard Height and Baluster Spacing: The 4-Inch Sphere - lesson diagram https://contractorsclassroom.com/landing-images/c23-handrail-profile-extensions/en/thumb-400.jpg Handrail Profile, Clearance, and Extensions - lesson diagram https://contractorsclassroom.com/landing-images/c23-accessible-ramp-rails/en/thumb-400.jpg Accessible Ramp Rails: Rise, Landings, Extensions, and Edge Protection - lesson diagram https://contractorsclassroom.com/landing-images/c23-guard-post-loads/en/thumb-400.jpg Guard and Handrail Loads: 200 lb, 50 plf, and the Post Base - lesson diagram https://contractorsclassroom.com/landing-images/c23-caltrans-railing-galvanizing/en/thumb-400.jpg Caltrans Railing Steel: Galvanizing Schedule, Coating Check, and Tubular-Rail Fit - lesson diagram https://contractorsclassroom.com/spanish/trades/c23-licencia-contratista-metal-ornamental-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c23/es/hero-1600.jpg Preparación para el examen de licencia de contratista de metal ornamental (C-23) https://contractorsclassroom.com/landing-images/c23-stair-stringer-layout/en/thumb-400.jpg Stair Stringer Layout: Riser Count, Tread Run, and Uniformity - lesson diagram https://contractorsclassroom.com/landing-images/c23-guard-baluster-spacing/en/thumb-400.jpg Guard Height and Baluster Spacing: The 4-Inch Sphere - lesson diagram https://contractorsclassroom.com/landing-images/c23-handrail-profile-extensions/en/thumb-400.jpg Handrail Profile, Clearance, and Extensions - lesson diagram https://contractorsclassroom.com/landing-images/c23-accessible-ramp-rails/en/thumb-400.jpg Accessible Ramp Rails: Rise, Landings, Extensions, and Edge Protection - lesson diagram https://contractorsclassroom.com/landing-images/c23-guard-post-loads/en/thumb-400.jpg Guard and Handrail Loads: 200 lb, 50 plf, and the Post Base - lesson diagram https://contractorsclassroom.com/landing-images/c23-caltrans-railing-galvanizing/en/thumb-400.jpg Caltrans Railing Steel: Galvanizing Schedule, Coating Check, and Tubular-Rail Fit - lesson diagram https://contractorsclassroom.com/trades/c27-landscaping-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c27/en/hero-1600.jpg Landscaping Contractor License Exam Prep (C-27) https://contractorsclassroom.com/landing-images/c27-water-budget-mawa-etwu/en/thumb-400.jpg Landscape Water Budget: MAWA vs. ETWU - lesson diagram https://contractorsclassroom.com/landing-images/c27-compost-mulch-takeoff/en/thumb-400.jpg Soil Prep Takeoff: Compost and Mulch Quantities (MWELO) - lesson diagram https://contractorsclassroom.com/landing-images/c27-irrigation-design-limits/en/thumb-400.jpg Irrigation Design Checks: Setbacks, Narrow Strips, Slopes, and Meters - lesson diagram https://contractorsclassroom.com/landing-images/c27-irrigation-backflow-device/en/thumb-400.jpg Backflow Protection for an Irrigation Supply (CPC Sec. 603) - lesson diagram https://contractorsclassroom.com/landing-images/c27-retaining-wall-permit-stability/en/thumb-400.jpg Retaining Walls: The 4-Foot Permit Line and the 1.5 Safety Factor - lesson diagram https://contractorsclassroom.com/landing-images/c27-tree-work-near-power-lines/en/thumb-400.jpg Tree Work Near Power Lines: The 10-Foot Rule and Who May Cross It - lesson diagram https://contractorsclassroom.com/spanish/trades/c27-licencia-contratista-paisajismo-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c27/es/hero-1600.jpg Preparación para el examen de licencia de contratista de paisajismo (C-27) https://contractorsclassroom.com/landing-images/c27-water-budget-mawa-etwu/en/thumb-400.jpg Landscape Water Budget: MAWA vs. ETWU - lesson diagram https://contractorsclassroom.com/landing-images/c27-compost-mulch-takeoff/en/thumb-400.jpg Soil Prep Takeoff: Compost and Mulch Quantities (MWELO) - lesson diagram https://contractorsclassroom.com/landing-images/c27-irrigation-design-limits/en/thumb-400.jpg Irrigation Design Checks: Setbacks, Narrow Strips, Slopes, and Meters - lesson diagram https://contractorsclassroom.com/landing-images/c27-irrigation-backflow-device/en/thumb-400.jpg Backflow Protection for an Irrigation Supply (CPC Sec. 603) - lesson diagram https://contractorsclassroom.com/landing-images/c27-retaining-wall-permit-stability/en/thumb-400.jpg Retaining Walls: The 4-Foot Permit Line and the 1.5 Safety Factor - lesson diagram https://contractorsclassroom.com/landing-images/c27-tree-work-near-power-lines/en/thumb-400.jpg Tree Work Near Power Lines: The 10-Foot Rule and Who May Cross It - lesson diagram https://contractorsclassroom.com/trades/c28-locksmith-lock-security-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c28/en/hero-1600.jpg Lock and Security Equipment Contractor License Exam Prep (C-28) https://contractorsclassroom.com/landing-images/c28-panic-hardware-rules/en/thumb-400.jpg Panic and Fire Exit Hardware: Where It Is Required and How to Size It - lesson diagram https://contractorsclassroom.com/landing-images/c28-inactive-leaf-bolts/en/thumb-400.jpg Bolts on the Inactive Leaf of a Pair of Doors (Table 1010.2.4) - lesson diagram https://contractorsclassroom.com/landing-images/c28-egress-door-lock-exceptions/en/thumb-400.jpg When Can an Egress Door Be Locked? Key Locks, Dwelling Doors and Classrooms - lesson diagram https://contractorsclassroom.com/landing-images/c28-electric-lock-egress-release/en/thumb-400.jpg Electrically Locked Egress Doors: Hardware Release and Sensor Release - lesson diagram https://contractorsclassroom.com/landing-images/c28-delayed-egress-locks/en/thumb-400.jpg Delayed Egress Locks: The 15-Second Rule, the Sign, and the Path Limit - lesson diagram https://contractorsclassroom.com/landing-images/c28-hardware-height-force-closers/en/thumb-400.jpg Door Hardware Height, Opening Force and Closer Timing - lesson diagram https://contractorsclassroom.com/spanish/trades/c28-licencia-contratista-cerrajeria-seguridad-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c28/es/hero-1600.jpg Preparación para el examen de licencia de contratista de cerraduras y equipos de seguridad (C-28) https://contractorsclassroom.com/landing-images/c28-panic-hardware-rules/en/thumb-400.jpg Panic and Fire Exit Hardware: Where It Is Required and How to Size It - lesson diagram https://contractorsclassroom.com/landing-images/c28-inactive-leaf-bolts/en/thumb-400.jpg Bolts on the Inactive Leaf of a Pair of Doors (Table 1010.2.4) - lesson diagram https://contractorsclassroom.com/landing-images/c28-egress-door-lock-exceptions/en/thumb-400.jpg When Can an Egress Door Be Locked? Key Locks, Dwelling Doors and Classrooms - lesson diagram https://contractorsclassroom.com/landing-images/c28-electric-lock-egress-release/en/thumb-400.jpg Electrically Locked Egress Doors: Hardware Release and Sensor Release - lesson diagram https://contractorsclassroom.com/landing-images/c28-delayed-egress-locks/en/thumb-400.jpg Delayed Egress Locks: The 15-Second Rule, the Sign, and the Path Limit - lesson diagram https://contractorsclassroom.com/landing-images/c28-hardware-height-force-closers/en/thumb-400.jpg Door Hardware Height, Opening Force and Closer Timing - lesson diagram https://contractorsclassroom.com/trades/c29-masonry-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c29/en/hero-1600.jpg Masonry Contractor License Exam Prep (C-29) https://contractorsclassroom.com/landing-images/c29-fireplace-hearth-firebox/en/thumb-400.jpg Masonry Fireplace: Hearth, Firebox Walls and Clearances - lesson diagram https://contractorsclassroom.com/landing-images/c29-fireplace-flue-sizing/en/thumb-400.jpg Sizing the Flue for a Masonry Fireplace - lesson diagram https://contractorsclassroom.com/landing-images/c29-chimney-height-clearances/en/thumb-400.jpg Chimney Height, Cricket, Spark Arrester and Clearances - lesson diagram https://contractorsclassroom.com/landing-images/c29-chimney-seismic-reinforcement/en/thumb-400.jpg Chimney Seismic Steel, Ties and Strap Anchors - lesson diagram https://contractorsclassroom.com/landing-images/c29-grouting-reinforced-masonry/en/thumb-400.jpg Grouting Reinforced Masonry: Lifts, Pours and Cleanouts - lesson diagram https://contractorsclassroom.com/landing-images/c29-mortar-types-batching/en/thumb-400.jpg Mortar Types and Batching by Volume - lesson diagram https://contractorsclassroom.com/spanish/trades/c29-licencia-contratista-mamposteria-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c29/es/hero-1600.jpg Preparación para el examen de licencia de contratista de mampostería (C-29) https://contractorsclassroom.com/landing-images/c29-fireplace-hearth-firebox/en/thumb-400.jpg Masonry Fireplace: Hearth, Firebox Walls and Clearances - lesson diagram https://contractorsclassroom.com/landing-images/c29-fireplace-flue-sizing/en/thumb-400.jpg Sizing the Flue for a Masonry Fireplace - lesson diagram https://contractorsclassroom.com/landing-images/c29-chimney-height-clearances/en/thumb-400.jpg Chimney Height, Cricket, Spark Arrester and Clearances - lesson diagram https://contractorsclassroom.com/landing-images/c29-chimney-seismic-reinforcement/en/thumb-400.jpg Chimney Seismic Steel, Ties and Strap Anchors - lesson diagram https://contractorsclassroom.com/landing-images/c29-grouting-reinforced-masonry/en/thumb-400.jpg Grouting Reinforced Masonry: Lifts, Pours and Cleanouts - lesson diagram https://contractorsclassroom.com/landing-images/c29-mortar-types-batching/en/thumb-400.jpg Mortar Types and Batching by Volume - lesson diagram https://contractorsclassroom.com/trades/c31-traffic-control-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c31/en/hero-1600.jpg Construction Zone Traffic Control Contractor License Exam Prep (C-31) https://contractorsclassroom.com/landing-images/c31-merging-taper-length-cone-count/en/thumb-400.jpg Merging Taper Length and Cone Count - lesson diagram https://contractorsclassroom.com/landing-images/c31-lane-closure-length-sign-spacing/en/thumb-400.jpg Freeway Lane Closure Length: Signs, Taper and Buffer - lesson diagram https://contractorsclassroom.com/landing-images/c31-flagger-station-stopping-distance/en/thumb-400.jpg Flagger Station Placement and One-Lane, Two-Way Control - lesson diagram https://contractorsclassroom.com/landing-images/c31-flagger-equipment-night-visibility/en/thumb-400.jpg Flagger Equipment, Signals and Night Visibility - lesson diagram https://contractorsclassroom.com/landing-images/c31-pcms-arrow-board-setup/en/thumb-400.jpg Portable Changeable Message Signs and Arrow Boards - lesson diagram https://contractorsclassroom.com/landing-images/c31-channelizing-device-specifications/en/thumb-400.jpg Cone, Drum and Channelizing Device Specifications - lesson diagram https://contractorsclassroom.com/spanish/trades/c31-licencia-contratista-control-trafico-obras-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c31/es/hero-1600.jpg Preparación para el examen de licencia de contratista de control de tráfico en obras (C-31) https://contractorsclassroom.com/landing-images/c31-merging-taper-length-cone-count/en/thumb-400.jpg Merging Taper Length and Cone Count - lesson diagram https://contractorsclassroom.com/landing-images/c31-lane-closure-length-sign-spacing/en/thumb-400.jpg Freeway Lane Closure Length: Signs, Taper and Buffer - lesson diagram https://contractorsclassroom.com/landing-images/c31-flagger-station-stopping-distance/en/thumb-400.jpg Flagger Station Placement and One-Lane, Two-Way Control - lesson diagram https://contractorsclassroom.com/landing-images/c31-flagger-equipment-night-visibility/en/thumb-400.jpg Flagger Equipment, Signals and Night Visibility - lesson diagram https://contractorsclassroom.com/landing-images/c31-pcms-arrow-board-setup/en/thumb-400.jpg Portable Changeable Message Signs and Arrow Boards - lesson diagram https://contractorsclassroom.com/landing-images/c31-channelizing-device-specifications/en/thumb-400.jpg Cone, Drum and Channelizing Device Specifications - lesson diagram https://contractorsclassroom.com/trades/c32-parking-highway-improvement-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c32/en/hero-1600.jpg Parking and Highway Improvement Contractor License Exam Prep (C-32) https://contractorsclassroom.com/landing-images/c32-accessible-parking-count/en/thumb-400.jpg Accessible Parking Count and Van Spaces - lesson diagram https://contractorsclassroom.com/landing-images/c32-accessible-stall-layout/en/thumb-400.jpg Accessible Stall Layout, Slope and Markings - lesson diagram https://contractorsclassroom.com/landing-images/c32-striping-paint-quantity/en/thumb-400.jpg Striping Paint Quantity: Linear Feet to Gallons - lesson diagram https://contractorsclassroom.com/landing-images/c32-marking-material-application/en/thumb-400.jpg Striping Materials: Temperature, Thickness and Acceptance Checks - lesson diagram https://contractorsclassroom.com/landing-images/c32-removing-old-markings/en/thumb-400.jpg Removing Obsolete Markings: Limits and Pay Quantity - lesson diagram https://contractorsclassroom.com/landing-images/c32-ev-charging-stall-counts/en/thumb-400.jpg EV Charging Stalls: Required Counts and Accessible Stalls - lesson diagram https://contractorsclassroom.com/spanish/trades/c32-licencia-contratista-estacionamientos-carreteras-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c32/es/hero-1600.jpg Preparación para el examen de licencia de contratista de estacionamientos y carreteras (C-32) https://contractorsclassroom.com/landing-images/c32-accessible-parking-count/en/thumb-400.jpg Accessible Parking Count and Van Spaces - lesson diagram https://contractorsclassroom.com/landing-images/c32-accessible-stall-layout/en/thumb-400.jpg Accessible Stall Layout, Slope and Markings - lesson diagram https://contractorsclassroom.com/landing-images/c32-striping-paint-quantity/en/thumb-400.jpg Striping Paint Quantity: Linear Feet to Gallons - lesson diagram https://contractorsclassroom.com/landing-images/c32-marking-material-application/en/thumb-400.jpg Striping Materials: Temperature, Thickness and Acceptance Checks - lesson diagram https://contractorsclassroom.com/landing-images/c32-removing-old-markings/en/thumb-400.jpg Removing Obsolete Markings: Limits and Pay Quantity - lesson diagram https://contractorsclassroom.com/landing-images/c32-ev-charging-stall-counts/en/thumb-400.jpg EV Charging Stalls: Required Counts and Accessible Stalls - lesson diagram https://contractorsclassroom.com/trades/c33-painting-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c33/en/hero-1600.jpg Painting Contractor License Exam Prep (C-33) https://contractorsclassroom.com/landing-images/c33-voc-regulatory-calculation/en/thumb-400.jpg VOC Content: Reading the CALGreen Coating Limits - lesson diagram https://contractorsclassroom.com/landing-images/c33-rrp-lead-safe-work/en/thumb-400.jpg Lead-Safe Painting: When the EPA RRP Rule Applies - lesson diagram https://contractorsclassroom.com/landing-images/c33-cal-osha-lead-trigger-tasks/en/thumb-400.jpg Lead on the Job: Cal/OSHA PEL, Action Level and Trigger Tasks - lesson diagram https://contractorsclassroom.com/landing-images/c33-interior-finish-classes/en/thumb-400.jpg Interior Finish Classes: What Can Go on the Wall - lesson diagram https://contractorsclassroom.com/landing-images/c33-steel-coating-weather-window/en/thumb-400.jpg Weather Window: When You May Coat Steel (Caltrans §59-1.03B) - lesson diagram https://contractorsclassroom.com/landing-images/c33-caltrans-coat-film-build/en/thumb-400.jpg Film Build: Checking Each Coat and the Total Against the Spec - lesson diagram https://contractorsclassroom.com/spanish/trades/c33-licencia-contratista-pintura-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c33/es/hero-1600.jpg Preparación para el examen de licencia de contratista de pintura (C-33) https://contractorsclassroom.com/landing-images/c33-voc-regulatory-calculation/en/thumb-400.jpg VOC Content: Reading the CALGreen Coating Limits - lesson diagram https://contractorsclassroom.com/landing-images/c33-rrp-lead-safe-work/en/thumb-400.jpg Lead-Safe Painting: When the EPA RRP Rule Applies - lesson diagram https://contractorsclassroom.com/landing-images/c33-cal-osha-lead-trigger-tasks/en/thumb-400.jpg Lead on the Job: Cal/OSHA PEL, Action Level and Trigger Tasks - lesson diagram https://contractorsclassroom.com/landing-images/c33-interior-finish-classes/en/thumb-400.jpg Interior Finish Classes: What Can Go on the Wall - lesson diagram https://contractorsclassroom.com/landing-images/c33-steel-coating-weather-window/en/thumb-400.jpg Weather Window: When You May Coat Steel (Caltrans §59-1.03B) - lesson diagram https://contractorsclassroom.com/landing-images/c33-caltrans-coat-film-build/en/thumb-400.jpg Film Build: Checking Each Coat and the Total Against the Spec - lesson diagram https://contractorsclassroom.com/trades/c34-pipeline-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c34/en/hero-1600.jpg Pipeline Contractor License Exam Prep (C-34) https://contractorsclassroom.com/landing-images/c34-trench-sloping-by-soil-type/en/thumb-400.jpg Sloping a Pipe Trench by Soil Type (Title 8 Appendix B) - lesson diagram https://contractorsclassroom.com/landing-images/c34-pipe-trench-width-bedding-backfill/en/thumb-400.jpg Pipe Trench Width, Bedding, and Backfill Lifts - lesson diagram https://contractorsclassroom.com/landing-images/c34-thrust-block-sizing/en/thumb-400.jpg Thrust Block Sizing at Bends, Tees, and Dead Ends - lesson diagram https://contractorsclassroom.com/landing-images/c34-gravity-pipe-leakage-testing/en/thumb-400.jpg Leakage Testing a Gravity Pipe: Exfiltration and Air Test - lesson diagram https://contractorsclassroom.com/landing-images/c34-cathodic-protection-gas-pipe-testing/en/thumb-400.jpg Cathodic Protection of Underground Steel Gas Pipe: Criteria and Test Schedule - lesson diagram https://contractorsclassroom.com/landing-images/c34-supply-line-pressure-test/en/thumb-400.jpg Pressure Testing a Trenched Supply Line (Method A) - lesson diagram https://contractorsclassroom.com/spanish/trades/c34-licencia-contratista-tuberias-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c34/es/hero-1600.jpg Preparación para el examen de licencia de contratista de tuberías (C-34) https://contractorsclassroom.com/landing-images/c34-trench-sloping-by-soil-type/en/thumb-400.jpg Sloping a Pipe Trench by Soil Type (Title 8 Appendix B) - lesson diagram https://contractorsclassroom.com/landing-images/c34-pipe-trench-width-bedding-backfill/en/thumb-400.jpg Pipe Trench Width, Bedding, and Backfill Lifts - lesson diagram https://contractorsclassroom.com/landing-images/c34-thrust-block-sizing/en/thumb-400.jpg Thrust Block Sizing at Bends, Tees, and Dead Ends - lesson diagram https://contractorsclassroom.com/landing-images/c34-gravity-pipe-leakage-testing/en/thumb-400.jpg Leakage Testing a Gravity Pipe: Exfiltration and Air Test - lesson diagram https://contractorsclassroom.com/landing-images/c34-cathodic-protection-gas-pipe-testing/en/thumb-400.jpg Cathodic Protection of Underground Steel Gas Pipe: Criteria and Test Schedule - lesson diagram https://contractorsclassroom.com/landing-images/c34-supply-line-pressure-test/en/thumb-400.jpg Pressure Testing a Trenched Supply Line (Method A) - lesson diagram https://contractorsclassroom.com/trades/c35-lathing-plastering-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c35/en/hero-1600.jpg Lathing and Plastering Contractor License Exam Prep (C-35) https://contractorsclassroom.com/landing-images/c35-plaster-thickness-by-base/en/thumb-400.jpg Minimum Plaster Thickness by Base and the Cubic-Foot Takeoff - lesson diagram https://contractorsclassroom.com/landing-images/c35-plaster-mix-proportions/en/thumb-400.jpg Reading Plaster Mix Proportions by Coat - lesson diagram https://contractorsclassroom.com/landing-images/c35-coat-count-and-cure-calendar/en/thumb-400.jpg Coat Counts and the Cure-Time Calendar - lesson diagram https://contractorsclassroom.com/landing-images/c35-lath-fastening-and-weep-screed/en/thumb-400.jpg Exterior Stucco: Lath Fastening and Weep Screed Layout - lesson diagram https://contractorsclassroom.com/landing-images/c35-fire-rated-plaster-equivalents/en/thumb-400.jpg Plaster in Fire-Rated Assemblies: Equivalents and Reinforcement - lesson diagram https://contractorsclassroom.com/landing-images/c35-plaster-scaffold-and-mixer-safety/en/thumb-400.jpg Plasterers Scaffold and Mixer Guard Rules - lesson diagram https://contractorsclassroom.com/spanish/trades/c35-licencia-contratista-enlucido-yeso-estuco-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c35/es/hero-1600.jpg Preparación para el examen de licencia de contratista de enlucido y yeso (C-35) https://contractorsclassroom.com/landing-images/c35-plaster-thickness-by-base/en/thumb-400.jpg Minimum Plaster Thickness by Base and the Cubic-Foot Takeoff - lesson diagram https://contractorsclassroom.com/landing-images/c35-plaster-mix-proportions/en/thumb-400.jpg Reading Plaster Mix Proportions by Coat - lesson diagram https://contractorsclassroom.com/landing-images/c35-coat-count-and-cure-calendar/en/thumb-400.jpg Coat Counts and the Cure-Time Calendar - lesson diagram https://contractorsclassroom.com/landing-images/c35-lath-fastening-and-weep-screed/en/thumb-400.jpg Exterior Stucco: Lath Fastening and Weep Screed Layout - lesson diagram https://contractorsclassroom.com/landing-images/c35-fire-rated-plaster-equivalents/en/thumb-400.jpg Plaster in Fire-Rated Assemblies: Equivalents and Reinforcement - lesson diagram https://contractorsclassroom.com/landing-images/c35-plaster-scaffold-and-mixer-safety/en/thumb-400.jpg Plasterers Scaffold and Mixer Guard Rules - lesson diagram https://contractorsclassroom.com/trades/c36-plumbing-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c36/en/hero-1600.jpg Plumbing Contractor License Exam Prep (C-36) https://contractorsclassroom.com/spanish/trades/c36-licencia-contratista-plomeria-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c36/es/hero-1600.jpg Preparación para el examen de licencia de contratista de plomería (C-36) https://contractorsclassroom.com/trades/c38-refrigeration-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c38/en/hero-1600.jpg Refrigeration Contractor License Exam Prep (C-38) https://contractorsclassroom.com/landing-images/c38-rcl-room-charge-limit/en/thumb-400.jpg Refrigerant Charge Limit for a Room: RCL from CMC Table 1102.3 - lesson diagram https://contractorsclassroom.com/landing-images/c38-machinery-room-emergency-ventilation/en/thumb-400.jpg Machinery Room Triggers and Emergency Exhaust (CMC 1106) - lesson diagram https://contractorsclassroom.com/landing-images/c38-relief-vent-back-pressure/en/thumb-400.jpg Relief Valve Vent Piping: Termination, Back Pressure and Length (CMC 1112) - lesson diagram https://contractorsclassroom.com/landing-images/c38-field-pressure-test-declaration/en/thumb-400.jpg Field Pressure Test: Pressure, Test Gas and Declaration (CMC 1116) - lesson diagram https://contractorsclassroom.com/landing-images/c38-calgreen-supermarket-leak-tight/en/thumb-400.jpg Supermarket Leak-Tight Installation: CALGreen 5.508.2 Pressure Test and Evacuation - lesson diagram https://contractorsclassroom.com/landing-images/c38-warehouse-condenser-limits/en/thumb-400.jpg Refrigerated Warehouse Condensers: Design Condensing Temperature and Efficiency (Energy Code 120.6(a)) - lesson diagram https://contractorsclassroom.com/spanish/trades/c38-licencia-contratista-refrigeracion-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c38/es/hero-1600.jpg Preparación para el examen de licencia de contratista de refrigeración (C-38) https://contractorsclassroom.com/landing-images/c38-rcl-room-charge-limit/en/thumb-400.jpg Refrigerant Charge Limit for a Room: RCL from CMC Table 1102.3 - lesson diagram https://contractorsclassroom.com/landing-images/c38-machinery-room-emergency-ventilation/en/thumb-400.jpg Machinery Room Triggers and Emergency Exhaust (CMC 1106) - lesson diagram https://contractorsclassroom.com/landing-images/c38-relief-vent-back-pressure/en/thumb-400.jpg Relief Valve Vent Piping: Termination, Back Pressure and Length (CMC 1112) - lesson diagram https://contractorsclassroom.com/landing-images/c38-field-pressure-test-declaration/en/thumb-400.jpg Field Pressure Test: Pressure, Test Gas and Declaration (CMC 1116) - lesson diagram https://contractorsclassroom.com/landing-images/c38-calgreen-supermarket-leak-tight/en/thumb-400.jpg Supermarket Leak-Tight Installation: CALGreen 5.508.2 Pressure Test and Evacuation - lesson diagram https://contractorsclassroom.com/landing-images/c38-warehouse-condenser-limits/en/thumb-400.jpg Refrigerated Warehouse Condensers: Design Condensing Temperature and Efficiency (Energy Code 120.6(a)) - lesson diagram https://contractorsclassroom.com/trades/c39-roofing-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c39/en/hero-1600.jpg Roofing Contractor License Exam Prep (C-39) https://contractorsclassroom.com/landing-images/c39-roof-area-squares-bundles/en/thumb-400.jpg Roof Area, Squares, and Shingle Bundles - lesson diagram https://contractorsclassroom.com/landing-images/c39-shingle-slope-underlayment/en/thumb-400.jpg Shingle Slope Limits and Underlayment Layers - lesson diagram https://contractorsclassroom.com/landing-images/c39-attic-ventilation-nfa/en/thumb-400.jpg Attic Ventilation: Net Free Area (1/150 and 1/300) - lesson diagram https://contractorsclassroom.com/landing-images/c39-low-slope-roofing-drainage/en/thumb-400.jpg Low-Slope Roofing: Minimum Slope and Drainage - lesson diagram https://contractorsclassroom.com/landing-images/c39-roofing-fall-protection-title8/en/thumb-400.jpg Roofing Fall Protection: Title 8 Sections 1730 and 1731 - lesson diagram https://contractorsclassroom.com/landing-images/c39-shingle-flashing-drip-edge/en/thumb-400.jpg Shingle Roof Flashing: Drip Edge, Step Flashing, Valleys, and Crickets - lesson diagram https://contractorsclassroom.com/spanish/trades/c39-licencia-contratista-techado-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c39/es/hero-1600.jpg Preparación para el examen de licencia de contratista de techado (C-39) https://contractorsclassroom.com/landing-images/c39-roof-area-squares-bundles/en/thumb-400.jpg Roof Area, Squares, and Shingle Bundles - lesson diagram https://contractorsclassroom.com/landing-images/c39-shingle-slope-underlayment/en/thumb-400.jpg Shingle Slope Limits and Underlayment Layers - lesson diagram https://contractorsclassroom.com/landing-images/c39-attic-ventilation-nfa/en/thumb-400.jpg Attic Ventilation: Net Free Area (1/150 and 1/300) - lesson diagram https://contractorsclassroom.com/landing-images/c39-low-slope-roofing-drainage/en/thumb-400.jpg Low-Slope Roofing: Minimum Slope and Drainage - lesson diagram https://contractorsclassroom.com/landing-images/c39-roofing-fall-protection-title8/en/thumb-400.jpg Roofing Fall Protection: Title 8 Sections 1730 and 1731 - lesson diagram https://contractorsclassroom.com/landing-images/c39-shingle-flashing-drip-edge/en/thumb-400.jpg Shingle Roof Flashing: Drip Edge, Step Flashing, Valleys, and Crickets - lesson diagram https://contractorsclassroom.com/trades/c42-sanitation-system-septic-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c42/en/hero-1600.jpg Sanitation System Contractor License Exam Prep (C-42) https://contractorsclassroom.com/landing-images/c42-septic-tank-capacity/en/thumb-400.jpg Sizing a Septic Tank: Bedrooms, Flow, and Compartments - lesson diagram https://contractorsclassroom.com/landing-images/c42-leach-field-area/en/thumb-400.jpg Sizing a Leach Field: Soil, Square Feet, and Trench Length - lesson diagram https://contractorsclassroom.com/landing-images/c42-seepage-pit-sizing/en/thumb-400.jpg Sizing a Seepage Pit: Sidewall Area and Block Count - lesson diagram https://contractorsclassroom.com/landing-images/c42-setback-distances/en/thumb-400.jpg Setback Distances: Reading Table H 101.8 - lesson diagram https://contractorsclassroom.com/landing-images/c42-building-sewer-lateral/en/thumb-400.jpg Building Sewer Laterals: Fall, Size, Trench, and Cleanouts - lesson diagram https://contractorsclassroom.com/landing-images/c42-septic-tank-entry-safety/en/thumb-400.jpg Entering a Septic Tank or Sewer: Confined-Space Atmosphere Rules - lesson diagram https://contractorsclassroom.com/spanish/trades/c42-licencia-contratista-saneamiento-septico-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c42/es/hero-1600.jpg Preparación para el examen de licencia de contratista de sistemas de saneamiento (C-42) https://contractorsclassroom.com/landing-images/c42-septic-tank-capacity/en/thumb-400.jpg Sizing a Septic Tank: Bedrooms, Flow, and Compartments - lesson diagram https://contractorsclassroom.com/landing-images/c42-leach-field-area/en/thumb-400.jpg Sizing a Leach Field: Soil, Square Feet, and Trench Length - lesson diagram https://contractorsclassroom.com/landing-images/c42-seepage-pit-sizing/en/thumb-400.jpg Sizing a Seepage Pit: Sidewall Area and Block Count - lesson diagram https://contractorsclassroom.com/landing-images/c42-setback-distances/en/thumb-400.jpg Setback Distances: Reading Table H 101.8 - lesson diagram https://contractorsclassroom.com/landing-images/c42-building-sewer-lateral/en/thumb-400.jpg Building Sewer Laterals: Fall, Size, Trench, and Cleanouts - lesson diagram https://contractorsclassroom.com/landing-images/c42-septic-tank-entry-safety/en/thumb-400.jpg Entering a Septic Tank or Sewer: Confined-Space Atmosphere Rules - lesson diagram https://contractorsclassroom.com/trades/c43-sheet-metal-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c43/en/hero-1600.jpg Sheet Metal Contractor License Exam Prep (C-43) https://contractorsclassroom.com/landing-images/c43-gutter-leader-sizing/en/thumb-400.jpg Sizing Gutters and Leaders: CPC Tables 1103.3 and 1103.1 - lesson diagram https://contractorsclassroom.com/landing-images/c43-product-conveying-duct-gauge/en/thumb-400.jpg Product-Conveying Duct Gauge: CMC Tables 506.2(1) and 506.2(2) - lesson diagram https://contractorsclassroom.com/landing-images/c43-type-i-hood-size-exhaust/en/thumb-400.jpg Type I Kitchen Hoods: Metal, Overhang, and Net Exhaust (CMC 508) - lesson diagram https://contractorsclassroom.com/landing-images/c43-grease-duct-slope-clearance/en/thumb-400.jpg Grease Duct: Gauge, Slope, Access, and Clearance (CMC 510 and 507.4) - lesson diagram https://contractorsclassroom.com/landing-images/c43-dryer-exhaust-duct-length/en/thumb-400.jpg Clothes Dryer Exhaust Duct: Length, Elbows, and Metal (CMC 504.4) - lesson diagram https://contractorsclassroom.com/landing-images/c43-metal-roof-panel-slope-materials/en/thumb-400.jpg Metal Roof Panels: Minimum Slope, Materials, and Fasteners (CBC 1507.4) - lesson diagram https://contractorsclassroom.com/spanish/trades/c43-licencia-contratista-chapa-metalica-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c43/es/hero-1600.jpg Preparación para el examen de licencia de contratista de chapa metálica (C-43) https://contractorsclassroom.com/landing-images/c43-gutter-leader-sizing/en/thumb-400.jpg Sizing Gutters and Leaders: CPC Tables 1103.3 and 1103.1 - lesson diagram https://contractorsclassroom.com/landing-images/c43-product-conveying-duct-gauge/en/thumb-400.jpg Product-Conveying Duct Gauge: CMC Tables 506.2(1) and 506.2(2) - lesson diagram https://contractorsclassroom.com/landing-images/c43-type-i-hood-size-exhaust/en/thumb-400.jpg Type I Kitchen Hoods: Metal, Overhang, and Net Exhaust (CMC 508) - lesson diagram https://contractorsclassroom.com/landing-images/c43-grease-duct-slope-clearance/en/thumb-400.jpg Grease Duct: Gauge, Slope, Access, and Clearance (CMC 510 and 507.4) - lesson diagram https://contractorsclassroom.com/landing-images/c43-dryer-exhaust-duct-length/en/thumb-400.jpg Clothes Dryer Exhaust Duct: Length, Elbows, and Metal (CMC 504.4) - lesson diagram https://contractorsclassroom.com/landing-images/c43-metal-roof-panel-slope-materials/en/thumb-400.jpg Metal Roof Panels: Minimum Slope, Materials, and Fasteners (CBC 1507.4) - lesson diagram https://contractorsclassroom.com/trades/c45-sign-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c45/en/hero-1600.jpg Sign Contractor License Exam Prep (C-45) https://contractorsclassroom.com/landing-images/c45-sign-wind-load-force/en/thumb-400.jpg Wind Inputs and Footing Load for a Sign (CBC 1609, 1605.2) - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-pier-embedment-depth/en/thumb-400.jpg Pier Embedment Depth for a Pole or Pylon Sign - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-lighting-power-energy/en/thumb-400.jpg Sign Lighting Power Limits (Energy Code Sec. 140.8) - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-disconnect-clearance-bonding/en/thumb-400.jpg Sign Disconnect, Height, and Line Clearance (Title 8 ESO) - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-accessible-tactile-11b/en/thumb-400.jpg Accessible Signs: Tactile Letters, Braille and Character Height (CBC 11B-703) - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-public-right-of-way/en/thumb-400.jpg Signs Over the Public Right-of-Way (CBC Chapter 32) - lesson diagram https://contractorsclassroom.com/spanish/trades/c45-licencia-contratista-letreros-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c45/es/hero-1600.jpg Preparación para el examen de licencia de contratista de letreros (C-45) https://contractorsclassroom.com/landing-images/c45-sign-wind-load-force/en/thumb-400.jpg Wind Inputs and Footing Load for a Sign (CBC 1609, 1605.2) - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-pier-embedment-depth/en/thumb-400.jpg Pier Embedment Depth for a Pole or Pylon Sign - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-lighting-power-energy/en/thumb-400.jpg Sign Lighting Power Limits (Energy Code Sec. 140.8) - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-disconnect-clearance-bonding/en/thumb-400.jpg Sign Disconnect, Height, and Line Clearance (Title 8 ESO) - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-accessible-tactile-11b/en/thumb-400.jpg Accessible Signs: Tactile Letters, Braille and Character Height (CBC 11B-703) - lesson diagram https://contractorsclassroom.com/landing-images/c45-sign-public-right-of-way/en/thumb-400.jpg Signs Over the Public Right-of-Way (CBC Chapter 32) - lesson diagram https://contractorsclassroom.com/trades/c46-solar-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c46/en/hero-1600.jpg Solar Contractor License Exam Prep (C-46) https://contractorsclassroom.com/landing-images/c46-sf-pv-size-equation/en/thumb-400.jpg Single-Family PV Sizing: Equation 150.1-C - lesson diagram https://contractorsclassroom.com/landing-images/c46-nonres-pv-bess-sizing/en/thumb-400.jpg Commercial PV and Battery Sizing: Section 140.10 - lesson diagram https://contractorsclassroom.com/landing-images/c46-roof-pathways-setbacks/en/thumb-400.jpg Rooftop PV Fire Access: Pathways and Ridge Setbacks - lesson diagram https://contractorsclassroom.com/landing-images/c46-rapid-shutdown-labels/en/thumb-400.jpg Rapid Shutdown Labels and DC Conductor Rules - lesson diagram https://contractorsclassroom.com/landing-images/c46-home-battery-siting-bess-ready/en/thumb-400.jpg Home Battery Systems: BESS-Ready Panels and Where Batteries May Go - lesson diagram https://contractorsclassroom.com/landing-images/c46-roof-loads-under-pv-array/en/thumb-400.jpg Roof Loads Under a PV Array: The Two Load Cases - lesson diagram https://contractorsclassroom.com/spanish/trades/c46-licencia-contratista-energia-solar-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c46/es/hero-1600.jpg Preparación para el examen de licencia de contratista de energía solar (C-46) https://contractorsclassroom.com/landing-images/c46-sf-pv-size-equation/en/thumb-400.jpg Single-Family PV Sizing: Equation 150.1-C - lesson diagram https://contractorsclassroom.com/landing-images/c46-nonres-pv-bess-sizing/en/thumb-400.jpg Commercial PV and Battery Sizing: Section 140.10 - lesson diagram https://contractorsclassroom.com/landing-images/c46-roof-pathways-setbacks/en/thumb-400.jpg Rooftop PV Fire Access: Pathways and Ridge Setbacks - lesson diagram https://contractorsclassroom.com/landing-images/c46-rapid-shutdown-labels/en/thumb-400.jpg Rapid Shutdown Labels and DC Conductor Rules - lesson diagram https://contractorsclassroom.com/landing-images/c46-home-battery-siting-bess-ready/en/thumb-400.jpg Home Battery Systems: BESS-Ready Panels and Where Batteries May Go - lesson diagram https://contractorsclassroom.com/landing-images/c46-roof-loads-under-pv-array/en/thumb-400.jpg Roof Loads Under a PV Array: The Two Load Cases - lesson diagram https://contractorsclassroom.com/trades/c47-manufactured-housing-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c47/en/hero-1600.jpg Manufactured Housing Contractor License Exam Prep (C-47) https://contractorsclassroom.com/landing-images/c47-soil-class-bearing/en/thumb-400.jpg Soil Bearing Values from the Presumptive Load-Bearing Table - lesson diagram https://contractorsclassroom.com/landing-images/c47-pier-footing-sizing/en/thumb-400.jpg Sizing Pier Footings from Pier Load and Soil Pressure - lesson diagram https://contractorsclassroom.com/landing-images/c47-block-pier-height-clearance/en/thumb-400.jpg Masonry Pier Height Limits and Wood-to-Ground Clearances - lesson diagram https://contractorsclassroom.com/landing-images/c47-lot-drain-water-connections/en/thumb-400.jpg Lot Drain Inlet, Drain Connector and Water Outlet - lesson diagram https://contractorsclassroom.com/landing-images/c47-site-gas-supply/en/thumb-400.jpg Gas Supply at the Home Site: Demand, Burial, Valves and Air Test - lesson diagram https://contractorsclassroom.com/landing-images/c47-crawlspace-ventilation-moisture/en/thumb-400.jpg Crawlspace Ventilation, Vapor Retarder and Site Drainage - lesson diagram https://contractorsclassroom.com/spanish/trades/c47-licencia-contratista-viviendas-prefabricadas-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c47/es/hero-1600.jpg Preparación para el examen de licencia de contratista de viviendas prefabricadas (C-47) https://contractorsclassroom.com/landing-images/c47-soil-class-bearing/en/thumb-400.jpg Soil Bearing Values from the Presumptive Load-Bearing Table - lesson diagram https://contractorsclassroom.com/landing-images/c47-pier-footing-sizing/en/thumb-400.jpg Sizing Pier Footings from Pier Load and Soil Pressure - lesson diagram https://contractorsclassroom.com/landing-images/c47-block-pier-height-clearance/en/thumb-400.jpg Masonry Pier Height Limits and Wood-to-Ground Clearances - lesson diagram https://contractorsclassroom.com/landing-images/c47-lot-drain-water-connections/en/thumb-400.jpg Lot Drain Inlet, Drain Connector and Water Outlet - lesson diagram https://contractorsclassroom.com/landing-images/c47-site-gas-supply/en/thumb-400.jpg Gas Supply at the Home Site: Demand, Burial, Valves and Air Test - lesson diagram https://contractorsclassroom.com/landing-images/c47-crawlspace-ventilation-moisture/en/thumb-400.jpg Crawlspace Ventilation, Vapor Retarder and Site Drainage - lesson diagram https://contractorsclassroom.com/trades/c50-reinforcing-steel-rebar-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c50/en/hero-1600.jpg Reinforcing Steel Contractor License Exam Prep (C-50) https://contractorsclassroom.com/landing-images/c50-bar-weight-takeoff/en/thumb-400.jpg Rebar Weight Takeoff: Bar Sizes, Cover, and Tons - lesson diagram https://contractorsclassroom.com/landing-images/c50-standard-hooks-cut-length/en/thumb-400.jpg Standard Hooks and Bend Dimensions: What the Code Page Prints - lesson diagram https://contractorsclassroom.com/landing-images/c50-lap-splice-length/en/thumb-400.jpg Lap Splice Length: What Caltrans Section 52 and the CRC Print - lesson diagram https://contractorsclassroom.com/landing-images/c50-cover-clear-spacing-fit/en/thumb-400.jpg Cover and Clear Spacing: Do the Bars Fit in the Member? - lesson diagram https://contractorsclassroom.com/landing-images/c50-footing-minimum-bars/en/thumb-400.jpg Minimum Bars in Footings and Plain Concrete Walls: Checking Bar Area - lesson diagram https://contractorsclassroom.com/landing-images/c50-rebar-impalement-protection/en/thumb-400.jpg Rebar Impalement Protection: Covers, Troughs, and the 7-1/2 Foot Test - lesson diagram https://contractorsclassroom.com/spanish/trades/c50-licencia-contratista-acero-de-refuerzo-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c50/es/hero-1600.jpg Preparación para el examen de licencia de contratista de acero de refuerzo (C-50) https://contractorsclassroom.com/landing-images/c50-bar-weight-takeoff/en/thumb-400.jpg Rebar Weight Takeoff: Bar Sizes, Cover, and Tons - lesson diagram https://contractorsclassroom.com/landing-images/c50-standard-hooks-cut-length/en/thumb-400.jpg Standard Hooks and Bend Dimensions: What the Code Page Prints - lesson diagram https://contractorsclassroom.com/landing-images/c50-lap-splice-length/en/thumb-400.jpg Lap Splice Length: What Caltrans Section 52 and the CRC Print - lesson diagram https://contractorsclassroom.com/landing-images/c50-cover-clear-spacing-fit/en/thumb-400.jpg Cover and Clear Spacing: Do the Bars Fit in the Member? - lesson diagram https://contractorsclassroom.com/landing-images/c50-footing-minimum-bars/en/thumb-400.jpg Minimum Bars in Footings and Plain Concrete Walls: Checking Bar Area - lesson diagram https://contractorsclassroom.com/landing-images/c50-rebar-impalement-protection/en/thumb-400.jpg Rebar Impalement Protection: Covers, Troughs, and the 7-1/2 Foot Test - lesson diagram https://contractorsclassroom.com/trades/c51-structural-steel-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c51/en/hero-1600.jpg Structural Steel Contractor License Exam Prep (C-51) https://contractorsclassroom.com/landing-images/c51-reading-shape-designations/en/thumb-400.jpg Reading Steel Callouts, Substitutions, and Material Identity - lesson diagram https://contractorsclassroom.com/landing-images/c51-steel-weight-takeoff/en/thumb-400.jpg Steel Weight Takeoff: Pounds per Foot, Plates, Welds, and Tons - lesson diagram https://contractorsclassroom.com/landing-images/c51-high-strength-bolt-tightening/en/thumb-400.jpg High-Strength Bolts: Assemblies, Holes, and Caltrans Verification Testing - lesson diagram https://contractorsclassroom.com/landing-images/c51-sling-angle-multiple-lift/en/thumb-400.jpg Sling Angles and the Multiple-Lift Rules - lesson diagram https://contractorsclassroom.com/landing-images/c51-column-anchorage-and-two-bolt-rule/en/thumb-400.jpg Column Anchorage, Two-Bolt Release, and Double Connections - lesson diagram https://contractorsclassroom.com/landing-images/c51-skeleton-steel-fall-protection/en/thumb-400.jpg Fall Protection on Skeleton Steel: Connector Heights, Perimeter Cable, and the CDZ - lesson diagram https://contractorsclassroom.com/spanish/trades/c51-licencia-contratista-acero-estructural-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c51/es/hero-1600.jpg Preparación para el examen de licencia de contratista de acero estructural (C-51) https://contractorsclassroom.com/landing-images/c51-reading-shape-designations/en/thumb-400.jpg Reading Steel Callouts, Substitutions, and Material Identity - lesson diagram https://contractorsclassroom.com/landing-images/c51-steel-weight-takeoff/en/thumb-400.jpg Steel Weight Takeoff: Pounds per Foot, Plates, Welds, and Tons - lesson diagram https://contractorsclassroom.com/landing-images/c51-high-strength-bolt-tightening/en/thumb-400.jpg High-Strength Bolts: Assemblies, Holes, and Caltrans Verification Testing - lesson diagram https://contractorsclassroom.com/landing-images/c51-sling-angle-multiple-lift/en/thumb-400.jpg Sling Angles and the Multiple-Lift Rules - lesson diagram https://contractorsclassroom.com/landing-images/c51-column-anchorage-and-two-bolt-rule/en/thumb-400.jpg Column Anchorage, Two-Bolt Release, and Double Connections - lesson diagram https://contractorsclassroom.com/landing-images/c51-skeleton-steel-fall-protection/en/thumb-400.jpg Fall Protection on Skeleton Steel: Connector Heights, Perimeter Cable, and the CDZ - lesson diagram https://contractorsclassroom.com/trades/c53-swimming-pool-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c53/en/hero-1600.jpg Swimming Pool Contractor License Exam Prep (C-53) https://contractorsclassroom.com/landing-images/c53-turnover-flow-rate-pump-head/en/thumb-400.jpg Turnover Time, Flow Rate, and Pump Head - lesson diagram https://contractorsclassroom.com/landing-images/c53-filter-area-backwash-pump-head/en/thumb-400.jpg Sizing a Filter: Flow Rate per Square Foot - lesson diagram https://contractorsclassroom.com/landing-images/c53-suction-outlets-entrapment-velocity/en/thumb-400.jpg Suction Outlets and Entrapment: Two Drains and the Velocity Limits - lesson diagram https://contractorsclassroom.com/landing-images/c53-floor-slope-depth-line-markers/en/thumb-400.jpg Pool Floor Slope, the 4-1/2 Foot Line, and Depth Markers - lesson diagram https://contractorsclassroom.com/landing-images/c53-deck-slope-coping-handholds/en/thumb-400.jpg Pool Deck Slope, Coping, and the 9-Inch Handhold - lesson diagram https://contractorsclassroom.com/landing-images/c53-pool-heater-energy-code-solar-sizing/en/thumb-400.jpg Pool Heaters and Solar: Energy Code Checklist and Collector Sizing - lesson diagram https://contractorsclassroom.com/spanish/trades/c53-licencia-contratista-piscinas-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c53/es/hero-1600.jpg Preparación para el examen de licencia de contratista de piscinas (C-53) https://contractorsclassroom.com/landing-images/c53-turnover-flow-rate-pump-head/en/thumb-400.jpg Turnover Time, Flow Rate, and Pump Head - lesson diagram https://contractorsclassroom.com/landing-images/c53-filter-area-backwash-pump-head/en/thumb-400.jpg Sizing a Filter: Flow Rate per Square Foot - lesson diagram https://contractorsclassroom.com/landing-images/c53-suction-outlets-entrapment-velocity/en/thumb-400.jpg Suction Outlets and Entrapment: Two Drains and the Velocity Limits - lesson diagram https://contractorsclassroom.com/landing-images/c53-floor-slope-depth-line-markers/en/thumb-400.jpg Pool Floor Slope, the 4-1/2 Foot Line, and Depth Markers - lesson diagram https://contractorsclassroom.com/landing-images/c53-deck-slope-coping-handholds/en/thumb-400.jpg Pool Deck Slope, Coping, and the 9-Inch Handhold - lesson diagram https://contractorsclassroom.com/landing-images/c53-pool-heater-energy-code-solar-sizing/en/thumb-400.jpg Pool Heaters and Solar: Energy Code Checklist and Collector Sizing - lesson diagram https://contractorsclassroom.com/trades/c54-tile-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c54/en/hero-1600.jpg Tile Contractor License Exam Prep (C-54) https://contractorsclassroom.com/landing-images/c54-tile-layout-balanced-cuts/en/thumb-400.jpg Tile Layout: Centering and Balanced Cuts (Practice) - lesson diagram https://contractorsclassroom.com/landing-images/c54-floor-deflection-tile/en/thumb-400.jpg Floor Framing Under Tile: L/360 and the Joist Span Table - lesson diagram https://contractorsclassroom.com/landing-images/c54-shower-receptor-slope-curb/en/thumb-400.jpg Shower Receptor: Slope, Curb, Lining Height and Flood Test - lesson diagram https://contractorsclassroom.com/landing-images/c54-backer-board-wet-wall-heights/en/thumb-400.jpg Backer Board and Wet-Wall Tile Heights - lesson diagram https://contractorsclassroom.com/landing-images/c54-accessible-shower-11b-608/en/thumb-400.jpg Accessible Shower Floors: Threshold, Slope and Grate - lesson diagram https://contractorsclassroom.com/landing-images/c54-tile-adhesive-voc-calgreen/en/thumb-400.jpg CALGreen VOC Limits: Tile Adhesives and Sealants - lesson diagram https://contractorsclassroom.com/spanish/trades/c54-licencia-contratista-azulejo-mosaico-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c54/es/hero-1600.jpg Preparación para el examen de licencia de contratista de azulejo y mosaico (C-54) https://contractorsclassroom.com/landing-images/c54-tile-layout-balanced-cuts/en/thumb-400.jpg Tile Layout: Centering and Balanced Cuts (Practice) - lesson diagram https://contractorsclassroom.com/landing-images/c54-floor-deflection-tile/en/thumb-400.jpg Floor Framing Under Tile: L/360 and the Joist Span Table - lesson diagram https://contractorsclassroom.com/landing-images/c54-shower-receptor-slope-curb/en/thumb-400.jpg Shower Receptor: Slope, Curb, Lining Height and Flood Test - lesson diagram https://contractorsclassroom.com/landing-images/c54-backer-board-wet-wall-heights/en/thumb-400.jpg Backer Board and Wet-Wall Tile Heights - lesson diagram https://contractorsclassroom.com/landing-images/c54-accessible-shower-11b-608/en/thumb-400.jpg Accessible Shower Floors: Threshold, Slope and Grate - lesson diagram https://contractorsclassroom.com/landing-images/c54-tile-adhesive-voc-calgreen/en/thumb-400.jpg CALGreen VOC Limits: Tile Adhesives and Sealants - lesson diagram https://contractorsclassroom.com/trades/c55-water-conditioning-softener-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c55/en/hero-1600.jpg Water Conditioning Contractor License Exam Prep (C-55) https://contractorsclassroom.com/landing-images/c55-softener-connection-sizing/en/thumb-400.jpg Sizing the Residential Softener Connection (CPC 611.4) - lesson diagram https://contractorsclassroom.com/landing-images/c55-treatment-drain-air-gap/en/thumb-400.jpg Air Gap on a Treatment-Unit Drain (CPC 611.2) - lesson diagram https://contractorsclassroom.com/landing-images/c55-softener-efficiency-hardness-limits/en/thumb-400.jpg Softener Efficiency and Hardness Limits (CPC Appendix L) - lesson diagram https://contractorsclassroom.com/landing-images/c55-softener-on-sprinklered-home/en/thumb-400.jpg Adding a Softener to a Sprinklered Home (CRC R309.3) - lesson diagram https://contractorsclassroom.com/landing-images/c55-chlorine-disinfection-dose/en/thumb-400.jpg Chlorine Disinfection: Dose and Safety (CPC 609.10) - lesson diagram https://contractorsclassroom.com/spanish/trades/c55-licencia-contratista-acondicionamiento-agua-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c55/es/hero-1600.jpg Preparación para el examen de licencia de contratista de acondicionamiento de agua (C-55) https://contractorsclassroom.com/landing-images/c55-softener-connection-sizing/en/thumb-400.jpg Sizing the Residential Softener Connection (CPC 611.4) - lesson diagram https://contractorsclassroom.com/landing-images/c55-treatment-drain-air-gap/en/thumb-400.jpg Air Gap on a Treatment-Unit Drain (CPC 611.2) - lesson diagram https://contractorsclassroom.com/landing-images/c55-softener-efficiency-hardness-limits/en/thumb-400.jpg Softener Efficiency and Hardness Limits (CPC Appendix L) - lesson diagram https://contractorsclassroom.com/landing-images/c55-softener-on-sprinklered-home/en/thumb-400.jpg Adding a Softener to a Sprinklered Home (CRC R309.3) - lesson diagram https://contractorsclassroom.com/landing-images/c55-chlorine-disinfection-dose/en/thumb-400.jpg Chlorine Disinfection: Dose and Safety (CPC 609.10) - lesson diagram https://contractorsclassroom.com/trades/c57-well-drilling-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c57/en/hero-1600.jpg Well Drilling Contractor License Exam Prep (C-57) https://contractorsclassroom.com/landing-images/c57-annular-seal-depth-and-volume/en/thumb-400.jpg Annular Seal: Depth, Hole Size, and Seal Volume - lesson diagram https://contractorsclassroom.com/landing-images/c57-well-site-separation-distances/en/thumb-400.jpg Siting a Well: Separation Distances and the Encroachment Seal - lesson diagram https://contractorsclassroom.com/landing-images/c57-annular-seal-mixes-and-limits/en/thumb-400.jpg Annular Seal Mixes: Ratios, Additives, and Set Times - lesson diagram https://contractorsclassroom.com/landing-images/c57-wellhead-pad-and-surface-seal/en/thumb-400.jpg Wellhead Pad and Surface Seal: Sizing the Base and Sealing Openings - lesson diagram https://contractorsclassroom.com/landing-images/c57-well-disinfection-dose/en/thumb-400.jpg Disinfecting a Well: Chlorine Dose from Table 6 - lesson diagram https://contractorsclassroom.com/landing-images/c57-well-destruction-fill-plan/en/thumb-400.jpg Destroying an Abandoned Well: Fill Plan and Volume Check - lesson diagram https://contractorsclassroom.com/spanish/trades/c57-licencia-contratista-perforacion-pozos-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c57/es/hero-1600.jpg Preparación para el examen de licencia de contratista de perforación de pozos (C-57) https://contractorsclassroom.com/landing-images/c57-annular-seal-depth-and-volume/en/thumb-400.jpg Annular Seal: Depth, Hole Size, and Seal Volume - lesson diagram https://contractorsclassroom.com/landing-images/c57-well-site-separation-distances/en/thumb-400.jpg Siting a Well: Separation Distances and the Encroachment Seal - lesson diagram https://contractorsclassroom.com/landing-images/c57-annular-seal-mixes-and-limits/en/thumb-400.jpg Annular Seal Mixes: Ratios, Additives, and Set Times - lesson diagram https://contractorsclassroom.com/landing-images/c57-wellhead-pad-and-surface-seal/en/thumb-400.jpg Wellhead Pad and Surface Seal: Sizing the Base and Sealing Openings - lesson diagram https://contractorsclassroom.com/landing-images/c57-well-disinfection-dose/en/thumb-400.jpg Disinfecting a Well: Chlorine Dose from Table 6 - lesson diagram https://contractorsclassroom.com/landing-images/c57-well-destruction-fill-plan/en/thumb-400.jpg Destroying an Abandoned Well: Fill Plan and Volume Check - lesson diagram https://contractorsclassroom.com/trades/c60-welding-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c60/en/hero-1600.jpg Welding Contractor License Exam Prep (C-60) https://contractorsclassroom.com/landing-images/c60-welding-filter-lens-shade/en/thumb-400.jpg Choosing the Filter Lens Shade (Table EP-1) - lesson diagram https://contractorsclassroom.com/landing-images/c60-welding-fume-twa-and-pel/en/thumb-400.jpg Welding Fume: Calculating the 8-Hour TWA and the Additive Limit - lesson diagram https://contractorsclassroom.com/landing-images/c60-welding-ventilation-and-coated-metals/en/thumb-400.jpg Welding Ventilation, Toxic Metals, and Coated Surfaces - lesson diagram https://contractorsclassroom.com/landing-images/c60-oxy-fuel-cylinders-hose-and-pressure/en/thumb-400.jpg Oxy-Fuel Setup: Cylinder Separation, Hose, and Pressure Limits - lesson diagram https://contractorsclassroom.com/landing-images/c60-hot-work-fire-watch-and-permit/en/thumb-400.jpg Hot Work: Permit, Fire Watch Timing, and the Extinguisher Rule - lesson diagram https://contractorsclassroom.com/landing-images/c60-arc-welding-return-cable-and-splices/en/thumb-400.jpg Arc Welding Circuit: Return Cable Capacity, Splices, and Shutdown - lesson diagram https://contractorsclassroom.com/spanish/trades/c60-licencia-contratista-soldadura-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c60/es/hero-1600.jpg Preparación para el examen de licencia de contratista de soldadura (C-60) https://contractorsclassroom.com/landing-images/c60-welding-filter-lens-shade/en/thumb-400.jpg Choosing the Filter Lens Shade (Table EP-1) - lesson diagram https://contractorsclassroom.com/landing-images/c60-welding-fume-twa-and-pel/en/thumb-400.jpg Welding Fume: Calculating the 8-Hour TWA and the Additive Limit - lesson diagram https://contractorsclassroom.com/landing-images/c60-welding-ventilation-and-coated-metals/en/thumb-400.jpg Welding Ventilation, Toxic Metals, and Coated Surfaces - lesson diagram https://contractorsclassroom.com/landing-images/c60-oxy-fuel-cylinders-hose-and-pressure/en/thumb-400.jpg Oxy-Fuel Setup: Cylinder Separation, Hose, and Pressure Limits - lesson diagram https://contractorsclassroom.com/landing-images/c60-hot-work-fire-watch-and-permit/en/thumb-400.jpg Hot Work: Permit, Fire Watch Timing, and the Extinguisher Rule - lesson diagram https://contractorsclassroom.com/landing-images/c60-arc-welding-return-cable-and-splices/en/thumb-400.jpg Arc Welding Circuit: Return Cable Capacity, Splices, and Shutdown - lesson diagram https://contractorsclassroom.com/trades/c61-limited-specialty-contractor-license-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/c61/en/hero-1600.jpg Limited Specialty Contractor License Exam Prep (C-61) https://contractorsclassroom.com/landing-images/c61-awning-clearance-projection-fabric/en/thumb-400.jpg D-03 Awnings: Clearance, Projection and Fabric Rules - lesson diagram https://contractorsclassroom.com/landing-images/c61-powered-door-gate-requirements/en/thumb-400.jpg D-28 Powered Doors and Automatic Gates: Leaf Count, Controls and Backup Power - lesson diagram https://contractorsclassroom.com/landing-images/c61-accessible-toilet-compartment-layout/en/thumb-400.jpg D-34 Toilet Partitions: Accessible Compartment Size, Door and Grab Bar Layout - lesson diagram https://contractorsclassroom.com/landing-images/c61-pool-pump-flow-head-piping/en/thumb-400.jpg D-35 Pool Pumps: Filtration Flow Limit, System Head and Piping Rules - lesson diagram https://contractorsclassroom.com/landing-images/c61-scaffold-duty-load-plank-span/en/thumb-400.jpg D-39 Scaffolding: Duty Class, 4-to-1 Design Load and Plank Spans - lesson diagram https://contractorsclassroom.com/landing-images/c61-tree-felling-notch-climbing-line-limits/en/thumb-400.jpg D-49 Tree Service: Felling Notch, Climbing Line and Power-Line Limits - lesson diagram https://contractorsclassroom.com/spanish/trades/c61-licencia-contratista-especialidad-limitada-examen 2026-10-14 https://contractorsclassroom.com/landing-images/c61/es/hero-1600.jpg Preparación para el examen de licencia de contratista de especialidad limitada (C-61) https://contractorsclassroom.com/landing-images/c61-awning-clearance-projection-fabric/en/thumb-400.jpg D-03 Awnings: Clearance, Projection and Fabric Rules - lesson diagram https://contractorsclassroom.com/landing-images/c61-powered-door-gate-requirements/en/thumb-400.jpg D-28 Powered Doors and Automatic Gates: Leaf Count, Controls and Backup Power - lesson diagram https://contractorsclassroom.com/landing-images/c61-accessible-toilet-compartment-layout/en/thumb-400.jpg D-34 Toilet Partitions: Accessible Compartment Size, Door and Grab Bar Layout - lesson diagram https://contractorsclassroom.com/landing-images/c61-pool-pump-flow-head-piping/en/thumb-400.jpg D-35 Pool Pumps: Filtration Flow Limit, System Head and Piping Rules - lesson diagram https://contractorsclassroom.com/landing-images/c61-scaffold-duty-load-plank-span/en/thumb-400.jpg D-39 Scaffolding: Duty Class, 4-to-1 Design Load and Plank Spans - lesson diagram https://contractorsclassroom.com/landing-images/c61-tree-felling-notch-climbing-line-limits/en/thumb-400.jpg D-49 Tree Service: Felling Notch, Climbing Line and Power-Line Limits - lesson diagram https://contractorsclassroom.com/trades/haz-hazardous-substance-removal-certification-exam-prep 2026-10-14 https://contractorsclassroom.com/landing-images/haz/en/hero-1600.jpg Hazardous Substance Removal Certification Exam Prep (HAZ) https://contractorsclassroom.com/landing-images/haz-hazwoper-training-hours/en/thumb-400.jpg HAZWOPER Training Hours: Who Needs 40, 24 and 8 - lesson diagram https://contractorsclassroom.com/landing-images/haz-ppe-level-selection/en/thumb-400.jpg Choosing a PPE Level: A, B, C or D on a Hazardous Site - lesson diagram https://contractorsclassroom.com/landing-images/haz-pel-twa-additive-exposure/en/thumb-400.jpg PELs, 8-Hour TWA and the Mixture Rule - lesson diagram https://contractorsclassroom.com/landing-images/haz-ust-closure-soil-samples/en/thumb-400.jpg UST Removal: Counting the Closure Soil Samples - lesson diagram https://contractorsclassroom.com/landing-images/haz-ust-out-of-service-closure-clock/en/thumb-400.jpg Out-of-Service Tanks: The 90-Day, One-Year and 365-Day Clocks - lesson diagram https://contractorsclassroom.com/landing-images/haz-ust-release-reporting-clock/en/thumb-400.jpg UST Releases: The 8-Hour, 24-Hour, 5-Day and 45-Day Clock - lesson diagram https://contractorsclassroom.com/spanish/trades/haz-certificacion-sustancias-peligrosas-examen 2026-10-14 https://contractorsclassroom.com/landing-images/haz/es/hero-1600.jpg Preparación para el examen de certificación de remoción de sustancias peligrosas (HAZ) https://contractorsclassroom.com/landing-images/haz-hazwoper-training-hours/en/thumb-400.jpg HAZWOPER Training Hours: Who Needs 40, 24 and 8 - lesson diagram https://contractorsclassroom.com/landing-images/haz-ppe-level-selection/en/thumb-400.jpg Choosing a PPE Level: A, B, C or D on a Hazardous Site - lesson diagram https://contractorsclassroom.com/landing-images/haz-pel-twa-additive-exposure/en/thumb-400.jpg PELs, 8-Hour TWA and the Mixture Rule - lesson diagram https://contractorsclassroom.com/landing-images/haz-ust-closure-soil-samples/en/thumb-400.jpg UST Removal: Counting the Closure Soil Samples - lesson diagram https://contractorsclassroom.com/landing-images/haz-ust-out-of-service-closure-clock/en/thumb-400.jpg Out-of-Service Tanks: The 90-Day, One-Year and 365-Day Clocks - lesson diagram https://contractorsclassroom.com/landing-images/haz-ust-release-reporting-clock/en/thumb-400.jpg UST Releases: The 8-Hour, 24-Hour, 5-Day and 45-Day Clock - lesson diagram https://contractorsclassroom.com/learn/california-contractor-law-and-business-exam-prep/lb-choosing-a-business-entity 2026-10-14 https://contractorsclassroom.com/landing-images/lb-choosing-a-business-entity/en/og.jpg Choosing a Business Entity: Liability, Taxes, and What Happens to the License - lesson diagram https://contractorsclassroom.com/learn/california-contractor-law-and-business-exam-prep/lb-qualifying-individual-rmo-rme 2026-10-14 https://contractorsclassroom.com/landing-images/lb-qualifying-individual-rmo-rme/en/og.jpg The Qualifying Individual: RMO, RME, and the 90-Day Replacement Clock - lesson diagram https://contractorsclassroom.com/learn/california-contractor-law-and-business-exam-prep/lb-bonds-insurance-workers-comp 2026-10-14 https://contractorsclassroom.com/landing-images/lb-bonds-insurance-workers-comp/en/og.jpg Bonds, Liability Insurance, and Workers’ Comp: What the License Requires on File - lesson diagram https://contractorsclassroom.com/learn/california-contractor-law-and-business-exam-prep/lb-home-improvement-contract-checklist 2026-10-14 https://contractorsclassroom.com/landing-images/lb-home-improvement-contract-checklist/en/og.jpg The Home Improvement Contract Checklist: Down Payment, Change Orders, and Right to Cancel - lesson diagram https://contractorsclassroom.com/learn/california-contractor-law-and-business-exam-prep/lb-preliminary-notice-and-lien-calendar 2026-10-14 https://contractorsclassroom.com/landing-images/lb-preliminary-notice-and-lien-calendar/en/og.jpg The Preliminary Notice and Mechanics Lien Calendar - lesson diagram https://contractorsclassroom.com/learn/california-contractor-law-and-business-exam-prep/lb-first-employee-abc-test-payroll 2026-10-14 https://contractorsclassroom.com/landing-images/lb-first-employee-abc-test-payroll/en/og.jpg Your First Employee: the ABC Test, Payroll Taxes, and Deposit Deadlines - lesson diagram https://contractorsclassroom.com/learn/california-contractor-law-and-business-exam-prep/lb-balance-sheet-current-and-quick-ratio 2026-10-14 https://contractorsclassroom.com/landing-images/lb-balance-sheet-current-and-quick-ratio/en/og.jpg Reading a Balance Sheet: Working Capital, Current Ratio, and Quick Ratio - lesson diagram https://contractorsclassroom.com/learn/california-contractor-law-and-business-exam-prep/lb-public-works-registration-bonds-prevailing-wage 2026-10-14 https://contractorsclassroom.com/landing-images/lb-public-works-registration-bonds-prevailing-wage/en/og.jpg Public Works Basics: DIR Registration, Bonds, Prevailing Wage, and Certified Payroll - lesson diagram https://contractorsclassroom.com/learn/asb-asbestos-certification-exam-prep/asb-certification-and-registration-100-sq-ft 2026-10-14 https://contractorsclassroom.com/landing-images/asb-certification-and-registration-100-sq-ft/en/og.jpg Who Needs the ASB Certification and DOSH Registration: The 100 Square Foot Line - lesson diagram https://contractorsclassroom.com/learn/asb-asbestos-certification-exam-prep/asb-exposure-assessment-and-monitoring 2026-10-14 https://contractorsclassroom.com/landing-images/asb-exposure-assessment-and-monitoring/en/og.jpg Exposure Assessment and Monitoring: PELs, the Initial Assessment, and the Negative Exposure Assessment - lesson diagram https://contractorsclassroom.com/learn/asb-asbestos-certification-exam-prep/asb-class-i-iv-work-training-and-competent-person 2026-10-14 https://contractorsclassroom.com/landing-images/asb-class-i-iv-work-training-and-competent-person/en/og.jpg Class I to IV Asbestos Work, Training Hours, and the Competent Person - lesson diagram https://contractorsclassroom.com/learn/asb-asbestos-certification-exam-prep/asb-medical-surveillance-and-recordkeeping 2026-10-14 https://contractorsclassroom.com/landing-images/asb-medical-surveillance-and-recordkeeping/en/og.jpg Medical Surveillance and Recordkeeping: The 30-Day Trigger and How Long to Keep Records - lesson diagram https://contractorsclassroom.com/learn/asb-asbestos-certification-exam-prep/asb-consultants-and-site-surveillance-technicians 2026-10-14 https://contractorsclassroom.com/landing-images/asb-consultants-and-site-surveillance-technicians/en/og.jpg Asbestos Consultants and Site Surveillance Technicians: What a Contractor May and May Not Do - lesson diagram https://contractorsclassroom.com/learn/asb-asbestos-certification-exam-prep/asb-finding-acm-pacm-presumption-and-building-survey 2026-10-14 https://contractorsclassroom.com/landing-images/asb-finding-acm-pacm-presumption-and-building-survey/en/og.jpg Finding the ACM: the PACM Presumption, the Building Survey, and Sampling Counts - lesson diagram https://contractorsclassroom.com/learn/b2-residential-remodeling-contractor-license-exam-prep/b2-basement-egress-window-well 2026-10-14 https://contractorsclassroom.com/landing-images/b2-basement-egress-window-well/en/og.jpg Basement Egress Window Wells: Size, Depth, and Ladder - lesson diagram https://contractorsclassroom.com/learn/b2-residential-remodeling-contractor-license-exam-prep/b2-attic-conversion-sloped-ceiling-area 2026-10-14 https://contractorsclassroom.com/landing-images/b2-attic-conversion-sloped-ceiling-area/en/og.jpg Attic Conversions: Counting Floor Area Under a Sloped Ceiling - lesson diagram https://contractorsclassroom.com/learn/b2-residential-remodeling-contractor-license-exam-prep/b2-remodel-smoke-co-alarm-count 2026-10-14 https://contractorsclassroom.com/landing-images/b2-remodel-smoke-co-alarm-count/en/og.jpg Smoke and CO Alarm Upgrades Triggered by a Remodel - lesson diagram https://contractorsclassroom.com/learn/b2-residential-remodeling-contractor-license-exam-prep/b2-lead-safe-6-20-square-foot-test 2026-10-14 https://contractorsclassroom.com/landing-images/b2-lead-safe-6-20-square-foot-test/en/og.jpg Lead-Safe Remodeling: The 6 and 20 Square-Foot Test - lesson diagram https://contractorsclassroom.com/learn/b2-residential-remodeling-contractor-license-exam-prep/b2-bearing-wall-removal-beam-bearing 2026-10-14 https://contractorsclassroom.com/landing-images/b2-bearing-wall-removal-beam-bearing/en/og.jpg Removing a Bearing Wall: Sizing the Replacement Girder From CRC Table R602.7(2) - lesson diagram https://contractorsclassroom.com/learn/c2-insulation-acoustical-contractor-license-exam-prep/c02-suspended-grid-takeoff 2026-10-14 https://contractorsclassroom.com/landing-images/c02-suspended-grid-takeoff/en/og.jpg Suspended Ceiling Grid Takeoff (2x4 Lay-In) - lesson diagram https://contractorsclassroom.com/learn/c2-insulation-acoustical-contractor-license-exam-prep/c02-ceiling-seismic-bracing-layout 2026-10-14 https://contractorsclassroom.com/landing-images/c02-ceiling-seismic-bracing-layout/en/og.jpg Seismic Bracing Rules for Suspended Ceilings - lesson diagram https://contractorsclassroom.com/learn/c2-insulation-acoustical-contractor-license-exam-prep/c02-blown-attic-bag-count 2026-10-14 https://contractorsclassroom.com/landing-images/c02-blown-attic-bag-count/en/og.jpg Blown-In Attic Insulation: R-Value, Weight and Bag Count - lesson diagram https://contractorsclassroom.com/learn/c2-insulation-acoustical-contractor-license-exam-prep/c02-spray-foam-board-feet 2026-10-14 https://contractorsclassroom.com/landing-images/c02-spray-foam-board-feet/en/og.jpg Spray Foam: Board Feet, Thickness and Lifts - lesson diagram https://contractorsclassroom.com/learn/c2-insulation-acoustical-contractor-license-exam-prep/c02-composite-stc-gaps 2026-10-14 https://contractorsclassroom.com/landing-images/c02-composite-stc-gaps/en/og.jpg Composite STC: What a Gap Does to a Sound-Rated Wall - lesson diagram https://contractorsclassroom.com/learn/c4-boiler-steam-fitting-contractor-license-exam-prep/c04-expansion-tank-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c04-expansion-tank-sizing/en/og.jpg Sizing a Closed Expansion Tank by CMC Section 1004.4 - lesson diagram https://contractorsclassroom.com/learn/c4-boiler-steam-fitting-contractor-license-exam-prep/c04-boiler-control-groups 2026-10-14 https://contractorsclassroom.com/landing-images/c04-boiler-control-groups/en/og.jpg Boiler Group and Required Controls (CMC Table 1003.2.1) - lesson diagram https://contractorsclassroom.com/learn/c4-boiler-steam-fitting-contractor-license-exam-prep/c04-boiler-room-combustion-air 2026-10-14 https://contractorsclassroom.com/landing-images/c04-boiler-room-combustion-air/en/og.jpg Combustion Air for a Boiler Room (CMC Chapter 7) - lesson diagram https://contractorsclassroom.com/learn/c4-boiler-steam-fitting-contractor-license-exam-prep/c04-hydronic-test-relief-discharge 2026-10-14 https://contractorsclassroom.com/landing-images/c04-hydronic-test-relief-discharge/en/og.jpg Hydronic Test Pressure and Relief Valve Discharge (CMC 1205.2, 1206.2) - lesson diagram https://contractorsclassroom.com/learn/c4-boiler-steam-fitting-contractor-license-exam-prep/c04-pipe-insulation-table-120-3 2026-10-14 https://contractorsclassroom.com/landing-images/c04-pipe-insulation-table-120-3/en/og.jpg Hydronic and Steam Pipe Insulation (Energy Code Table 120.3-A-1) - lesson diagram https://contractorsclassroom.com/learn/c4-boiler-steam-fitting-contractor-license-exam-prep/c04-boiler-energy-code-return-water 2026-10-14 https://contractorsclassroom.com/landing-images/c04-boiler-energy-code-return-water/en/og.jpg Boiler Energy Code Rules: Input Size and Return Water Temperature - lesson diagram https://contractorsclassroom.com/learn/c4-boiler-steam-fitting-contractor-license-exam-prep/c04-boiler-entry-isolation 2026-10-14 https://contractorsclassroom.com/landing-images/c04-boiler-entry-isolation/en/og.jpg Entering a Boiler: Isolation, Blinding and Double Block and Bleed (8 CCR 3312) - lesson diagram https://contractorsclassroom.com/learn/c5-framing-carpentry-contractor-license-exam-prep/c05-notching-boring-limits 2026-10-14 https://contractorsclassroom.com/landing-images/c05-notching-boring-limits/en/og.jpg Notching and Boring Limits for Joists, Rafters, and Studs - lesson diagram https://contractorsclassroom.com/learn/c5-framing-carpentry-contractor-license-exam-prep/c05-joist-deflection-check 2026-10-14 https://contractorsclassroom.com/landing-images/c05-joist-deflection-check/en/og.jpg Floor Joist Deflection: The L/360 Limit and the Span Table - lesson diagram https://contractorsclassroom.com/learn/c5-framing-carpentry-contractor-license-exam-prep/c05-sill-plate-anchor-bolts 2026-10-14 https://contractorsclassroom.com/landing-images/c05-sill-plate-anchor-bolts/en/og.jpg Sill Plate Anchor Bolts: Spacing, End Distance, and Counting - lesson diagram https://contractorsclassroom.com/learn/c5-framing-carpentry-contractor-license-exam-prep/c05-deck-ledger-fastening 2026-10-14 https://contractorsclassroom.com/landing-images/c05-deck-ledger-fastening/en/og.jpg Deck Ledger Fastening: Lag Screw Spacing and Lateral Ties - lesson diagram https://contractorsclassroom.com/learn/c5-framing-carpentry-contractor-license-exam-prep/c05-shear-wall-nail-count 2026-10-14 https://contractorsclassroom.com/landing-images/c05-shear-wall-nail-count/en/og.jpg Shear Wall Fastening: Edge and Field Spacing, Fastener Counts, and 3x Framing - lesson diagram https://contractorsclassroom.com/learn/c6-cabinet-finish-carpentry-contractor-license-exam-prep/c06-crown-molding-compound-miters 2026-10-14 https://contractorsclassroom.com/landing-images/c06-crown-molding-compound-miters/en/og.jpg Crown Molding: Spring Angle and Compound Miter Settings - lesson diagram https://contractorsclassroom.com/learn/c6-cabinet-finish-carpentry-contractor-license-exam-prep/c06-stair-riser-tread-layout 2026-10-14 https://contractorsclassroom.com/landing-images/c06-stair-riser-tread-layout/en/og.jpg Stair Layout: Rise, Run, and Baluster Spacing - lesson diagram https://contractorsclassroom.com/learn/c6-cabinet-finish-carpentry-contractor-license-exam-prep/c06-prehung-door-opening-and-clearance 2026-10-14 https://contractorsclassroom.com/landing-images/c06-prehung-door-opening-and-clearance/en/og.jpg Doors: Clear Width, Clear Height, and Hardware Checks - lesson diagram https://contractorsclassroom.com/learn/c6-cabinet-finish-carpentry-contractor-license-exam-prep/c06-accessible-sink-base-clearances 2026-10-14 https://contractorsclassroom.com/landing-images/c06-accessible-sink-base-clearances/en/og.jpg Accessible Sink Cabinets: Counter Height and Knee Clearance - lesson diagram https://contractorsclassroom.com/learn/c6-cabinet-finish-carpentry-contractor-license-exam-prep/c06-accessible-kitchen-clearances 2026-10-14 https://contractorsclassroom.com/landing-images/c06-accessible-kitchen-clearances/en/og.jpg Accessible Kitchens: Aisle Clearances and Work Surface - lesson diagram https://contractorsclassroom.com/learn/c6-cabinet-finish-carpentry-contractor-license-exam-prep/c06-composite-wood-formaldehyde-and-voc-limits 2026-10-14 https://contractorsclassroom.com/landing-images/c06-composite-wood-formaldehyde-and-voc-limits/en/og.jpg Cabinet Materials: Formaldehyde and VOC Limits - lesson diagram https://contractorsclassroom.com/learn/c7-low-voltage-systems-contractor-license-exam-prep/c07-low-voltage-dc-voltage-drop 2026-10-14 https://contractorsclassroom.com/landing-images/c07-low-voltage-dc-voltage-drop/en/og.jpg Voltage Drop on Low-Voltage DC Runs (Locks, Cameras, Sounders) - lesson diagram https://contractorsclassroom.com/learn/c7-low-voltage-systems-contractor-license-exam-prep/c07-class2-power-source-limits 2026-10-14 https://contractorsclassroom.com/landing-images/c07-class2-power-source-limits/en/og.jpg Class 2 Power Source Limits: How Big a Supply Can One Circuit Use - lesson diagram https://contractorsclassroom.com/learn/c7-low-voltage-systems-contractor-license-exam-prep/c07-circuit-separation-rules 2026-10-14 https://contractorsclassroom.com/landing-images/c07-circuit-separation-rules/en/og.jpg Keeping Low-Voltage, Fire Alarm and Communications Wiring Apart - lesson diagram https://contractorsclassroom.com/learn/c7-low-voltage-systems-contractor-license-exam-prep/c07-fire-alarm-cfc-907-numbers 2026-10-14 https://contractorsclassroom.com/landing-images/c07-fire-alarm-cfc-907-numbers/en/og.jpg Fire Alarm Layout Numbers Printed in CFC Section 907 - lesson diagram https://contractorsclassroom.com/learn/c8-concrete-contractor-license-exam-prep/reading-a-rebar-callout 2026-10-14 https://contractorsclassroom.com/landing-images/reading-a-rebar-callout/en/og.jpg Reading a Rebar Callout - lesson diagram https://contractorsclassroom.com/learn/c8-concrete-contractor-license-exam-prep/c08-footing-size-tables 2026-10-14 https://contractorsclassroom.com/landing-images/c08-footing-size-tables/en/og.jpg Sizing a Footing from the CRC Tables - lesson diagram https://contractorsclassroom.com/learn/c8-concrete-contractor-license-exam-prep/c08-strength-weathering-air 2026-10-14 https://contractorsclassroom.com/landing-images/c08-strength-weathering-air/en/og.jpg Specified Strength and Air Entrainment by Exposure - lesson diagram https://contractorsclassroom.com/learn/c8-concrete-contractor-license-exam-prep/c08-slab-on-ground-requirements 2026-10-14 https://contractorsclassroom.com/landing-images/c08-slab-on-ground-requirements/en/og.jpg Slab-on-Ground: Thickness, Base, Vapor Retarder and Capillary Break - lesson diagram https://contractorsclassroom.com/learn/c8-concrete-contractor-license-exam-prep/c08-concrete-special-inspection 2026-10-14 https://contractorsclassroom.com/landing-images/c08-concrete-special-inspection/en/og.jpg When Concrete Work Needs Special Inspection (CBC Table 1705.3) - lesson diagram https://contractorsclassroom.com/learn/c8-concrete-contractor-license-exam-prep/c08-caltrans-slump-water-delivery 2026-10-14 https://contractorsclassroom.com/landing-images/c08-caltrans-slump-water-delivery/en/og.jpg Caltrans Concrete: Slump Limits, Free Water and Delivery Time - lesson diagram https://contractorsclassroom.com/learn/c8-concrete-contractor-license-exam-prep/c08-caltrans-curing-methods 2026-10-14 https://contractorsclassroom.com/landing-images/c08-caltrans-curing-methods/en/og.jpg Caltrans Concrete Curing Methods and Periods - lesson diagram https://contractorsclassroom.com/learn/c9-drywall-contractor-license-exam-prep/c09-steel-framing-thickness-screws 2026-10-14 https://contractorsclassroom.com/landing-images/c09-steel-framing-thickness-screws/en/og.jpg Steel Framing Thickness and Screw Selection for Board - lesson diagram https://contractorsclassroom.com/learn/c9-drywall-contractor-license-exam-prep/c09-fastener-spacing-screw-count 2026-10-14 https://contractorsclassroom.com/landing-images/c09-fastener-spacing-screw-count/en/og.jpg Screw Spacing and Screw Count per Sheet - lesson diagram https://contractorsclassroom.com/learn/c9-drywall-contractor-license-exam-prep/c09-fire-rated-wall-layers-takeoff 2026-10-14 https://contractorsclassroom.com/landing-images/c09-fire-rated-wall-layers-takeoff/en/og.jpg Fire-Rated Partitions: Layers, Offset Joints, and Board Takeoff - lesson diagram https://contractorsclassroom.com/learn/c9-drywall-contractor-license-exam-prep/c09-rated-wall-boxes-signs 2026-10-14 https://contractorsclassroom.com/landing-images/c09-rated-wall-boxes-signs/en/og.jpg Rated Walls: Box Openings and Concealed-Space Signs - lesson diagram https://contractorsclassroom.com/learn/c9-drywall-contractor-license-exam-prep/c09-diaphragm-ceiling-fasteners 2026-10-14 https://contractorsclassroom.com/landing-images/c09-diaphragm-ceiling-fasteners/en/og.jpg Gypsum Board Diaphragm Ceilings: Nails, Spacing, and Capacity - lesson diagram https://contractorsclassroom.com/learn/c10-electrical-contractor-electrician-license-exam-prep/c10-lockout-tagout-energized-work 2026-10-14 https://contractorsclassroom.com/landing-images/c10-lockout-tagout-energized-work/en/og.jpg Lockout/Tagout and Working on Energized Equipment - lesson diagram https://contractorsclassroom.com/learn/c10-electrical-contractor-electrician-license-exam-prep/c10-temporary-power-gfci-aegcp 2026-10-14 https://contractorsclassroom.com/landing-images/c10-temporary-power-gfci-aegcp/en/og.jpg Temporary Power: GFCIs and the Assured Grounding Program - lesson diagram https://contractorsclassroom.com/learn/c10-electrical-contractor-electrician-license-exam-prep/c10-voltage-drop-table-8 2026-10-14 https://contractorsclassroom.com/landing-images/c10-voltage-drop-table-8/en/og.jpg Voltage Drop with CEC Chapter 9 Table 8 - lesson diagram https://contractorsclassroom.com/learn/c10-electrical-contractor-electrician-license-exam-prep/c10-panel-working-space 2026-10-14 https://contractorsclassroom.com/landing-images/c10-panel-working-space/en/og.jpg Working Space and Dedicated Space at Panels - lesson diagram https://contractorsclassroom.com/learn/c10-electrical-contractor-electrician-license-exam-prep/c10-residential-lighting-controls 2026-10-14 https://contractorsclassroom.com/landing-images/c10-residential-lighting-controls/en/og.jpg Residential Lighting Controls and Blank Boxes (Energy Code §150.0(k)) - lesson diagram https://contractorsclassroom.com/learn/c10-electrical-contractor-electrician-license-exam-prep/c10-standby-power-generators 2026-10-14 https://contractorsclassroom.com/landing-images/c10-standby-power-generators/en/og.jpg Standby Power, Generators and Back-Feed - lesson diagram https://contractorsclassroom.com/learn/c11-elevator-contractor-license-exam-prep/c11-hoistway-vent-area 2026-10-14 https://contractorsclassroom.com/landing-images/c11-hoistway-vent-area/en/og.jpg Hoistway Vent Area and Operation - lesson diagram https://contractorsclassroom.com/learn/c11-elevator-contractor-license-exam-prep/c11-accessible-car-door-timing 2026-10-14 https://contractorsclassroom.com/landing-images/c11-accessible-car-door-timing/en/og.jpg Accessible Car Size and Door Timing - lesson diagram https://contractorsclassroom.com/learn/c11-elevator-contractor-license-exam-prep/c11-hoistway-fire-rating 2026-10-14 https://contractorsclassroom.com/landing-images/c11-hoistway-fire-rating/en/og.jpg Hoistway Fire Rating and Machine Room Enclosure - lesson diagram https://contractorsclassroom.com/learn/c11-elevator-contractor-license-exam-prep/c11-cab-lighting-fan-energy 2026-10-14 https://contractorsclassroom.com/landing-images/c11-cab-lighting-fan-energy/en/og.jpg Elevator Cab Lighting and Fan Energy Limits - lesson diagram https://contractorsclassroom.com/learn/c12-earthwork-paving-contractor-license-exam-prep/c12-hma-tonnage-spread-rate 2026-10-14 https://contractorsclassroom.com/landing-images/c12-hma-tonnage-spread-rate/en/og.jpg Hot Mix Asphalt Tonnage and the Spread-Rate Check - lesson diagram https://contractorsclassroom.com/learn/c12-earthwork-paving-contractor-license-exam-prep/c12-relative-compaction-field-test 2026-10-14 https://contractorsclassroom.com/landing-images/c12-relative-compaction-field-test/en/og.jpg Relative Compaction: Reading a Nuclear-Gauge Density Test - lesson diagram https://contractorsclassroom.com/learn/c12-earthwork-paving-contractor-license-exam-prep/c12-cut-fill-swell-shrink 2026-10-14 https://contractorsclassroom.com/landing-images/c12-cut-fill-swell-shrink/en/og.jpg Balancing Cut and Fill: Bank, Loose, and Compacted Yards - lesson diagram https://contractorsclassroom.com/learn/c12-earthwork-paving-contractor-license-exam-prep/c12-aggregate-base-tonnage 2026-10-14 https://contractorsclassroom.com/landing-images/c12-aggregate-base-tonnage/en/og.jpg Aggregate Base: Tons to Order, Lifts, and Grade Tolerance - lesson diagram https://contractorsclassroom.com/learn/c12-earthwork-paving-contractor-license-exam-prep/c12-paver-speed-truck-scheduling 2026-10-14 https://contractorsclassroom.com/landing-images/c12-paver-speed-truck-scheduling/en/og.jpg Matching Paver Speed to Plant Output and Truck Count - lesson diagram https://contractorsclassroom.com/learn/c12-earthwork-paving-contractor-license-exam-prep/c12-tack-coat-spray-rates 2026-10-14 https://contractorsclassroom.com/landing-images/c12-tack-coat-spray-rates/en/og.jpg Tack Coat: Residual Rate, Spray Rate, and Dilution - lesson diagram https://contractorsclassroom.com/learn/c13-fencing-contractor-license-exam-prep/c13-call-811-before-digging 2026-10-14 https://contractorsclassroom.com/landing-images/c13-call-811-before-digging/en/og.jpg Before You Dig Post Holes: The 811 Ticket and Marking Rules - lesson diagram https://contractorsclassroom.com/learn/c13-fencing-contractor-license-exam-prep/c13-chain-link-footing-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c13-chain-link-footing-sizing/en/og.jpg Chain-Link Post Footings: Caltrans Standard Plan A85 - lesson diagram https://contractorsclassroom.com/learn/c13-fencing-contractor-license-exam-prep/c13-embedded-post-eq-18-1 2026-10-14 https://contractorsclassroom.com/landing-images/c13-embedded-post-eq-18-1/en/og.jpg Post Embedment Depth: CBC Equation 18-1 and Table 1806.2 - lesson diagram https://contractorsclassroom.com/learn/c13-fencing-contractor-license-exam-prep/c13-chain-link-takeoff 2026-10-14 https://contractorsclassroom.com/landing-images/c13-chain-link-takeoff/en/og.jpg Chain-Link Takeoff: Posts, Braces, Fabric, and Fasteners - lesson diagram https://contractorsclassroom.com/learn/c13-fencing-contractor-license-exam-prep/c13-gate-post-size-slide-geometry 2026-10-14 https://contractorsclassroom.com/landing-images/c13-gate-post-size-slide-geometry/en/og.jpg Gates: Gate Posts, Width Limits, and California Building Code Gate Rules - lesson diagram https://contractorsclassroom.com/learn/c13-fencing-contractor-license-exam-prep/c13-pool-barrier-fence-gate-rules 2026-10-14 https://contractorsclassroom.com/landing-images/c13-pool-barrier-fence-gate-rules/en/og.jpg Pool Barrier Fence and Gate Rules (HSC §115923, 2025 CRC Appendix CI) - lesson diagram https://contractorsclassroom.com/learn/c15-flooring-contractor-license-exam-prep/c15-slab-vapor-retarder-capillary-break 2026-10-14 https://contractorsclassroom.com/landing-images/c15-slab-vapor-retarder-capillary-break/en/og.jpg Slab Moisture: Vapor Retarder and Capillary Break Under the Slab - lesson diagram https://contractorsclassroom.com/learn/c15-flooring-contractor-license-exam-prep/c15-subfloor-underlayment-crc-r503 2026-10-14 https://contractorsclassroom.com/landing-images/c15-subfloor-underlayment-crc-r503/en/og.jpg Subfloor Panels and Underlayment: Spans, Edge Support, and Particleboard - lesson diagram https://contractorsclassroom.com/learn/c15-flooring-contractor-license-exam-prep/c15-silica-floor-grinding-8ccr-1532-3 2026-10-14 https://contractorsclassroom.com/landing-images/c15-silica-floor-grinding-8ccr-1532-3/en/og.jpg Dust Control When Grinding Floors: 8 CCR 1532.3 Table 1 - lesson diagram https://contractorsclassroom.com/learn/c15-flooring-contractor-license-exam-prep/c15-calgreen-flooring-adhesive-voc-80-percent 2026-10-14 https://contractorsclassroom.com/landing-images/c15-calgreen-flooring-adhesive-voc-80-percent/en/og.jpg CALGreen Flooring Products: Adhesive VOC Limits and the 80% Rule - lesson diagram https://contractorsclassroom.com/learn/c15-flooring-contractor-license-exam-prep/c15-floor-finish-fire-class-cbc-804 2026-10-14 https://contractorsclassroom.com/landing-images/c15-floor-finish-fire-class-cbc-804/en/og.jpg Floor Finish Fire Class: Radiant Flux Classes and Where They Apply - lesson diagram https://contractorsclassroom.com/learn/c15-flooring-contractor-license-exam-prep/c15-floor-transitions-changes-in-level 2026-10-14 https://contractorsclassroom.com/landing-images/c15-floor-transitions-changes-in-level/en/og.jpg Floor Transitions: Changes in Level, Thresholds, and Carpet Edges - lesson diagram https://contractorsclassroom.com/learn/c15-flooring-contractor-license-exam-prep/c15-carpet-breadth-layout-pattern-repeat 2026-10-14 https://contractorsclassroom.com/landing-images/c15-carpet-breadth-layout-pattern-repeat/en/og.jpg Carpet Layout: Breadths, Seams, and Pattern Repeat - lesson diagram https://contractorsclassroom.com/learn/c16-fire-protection-sprinkler-contractor-license-exam-prep/c16-sprinkler-required-triggers 2026-10-14 https://contractorsclassroom.com/landing-images/c16-sprinkler-required-triggers/en/og.jpg Where Sprinklers Are Required: CFC 903.2 Triggers - lesson diagram https://contractorsclassroom.com/learn/c16-fire-protection-sprinkler-contractor-license-exam-prep/c16-required-fire-flow-appendix-b 2026-10-14 https://contractorsclassroom.com/landing-images/c16-required-fire-flow-appendix-b/en/og.jpg Required Fire Flow: California Fire Code Appendix B - lesson diagram https://contractorsclassroom.com/learn/c16-fire-protection-sprinkler-contractor-license-exam-prep/c16-hydrant-count-and-spacing 2026-10-14 https://contractorsclassroom.com/landing-images/c16-hydrant-count-and-spacing/en/og.jpg Hydrant Count and Spacing: California Fire Code Appendix C - lesson diagram https://contractorsclassroom.com/learn/c16-fire-protection-sprinkler-contractor-license-exam-prep/c16-standpipe-hose-connections-and-fdc 2026-10-14 https://contractorsclassroom.com/landing-images/c16-standpipe-hose-connections-and-fdc/en/og.jpg Standpipe Hose Connections and Fire Department Connections - lesson diagram https://contractorsclassroom.com/learn/c16-fire-protection-sprinkler-contractor-license-exam-prep/c16-fire-pump-room-requirements 2026-10-14 https://contractorsclassroom.com/landing-images/c16-fire-pump-room-requirements/en/og.jpg Fire Pump Room Requirements: CFC and CBC Section 913 - lesson diagram https://contractorsclassroom.com/learn/c16-fire-protection-sprinkler-contractor-license-exam-prep/c16-ca-amendments-nfpa-13-24 2026-10-14 https://contractorsclassroom.com/landing-images/c16-ca-amendments-nfpa-13-24/en/og.jpg California Amendments to NFPA 13 and NFPA 24 (CFC Chapter 80) - lesson diagram https://contractorsclassroom.com/learn/c17-glazing-glass-contractor-license-exam-prep/c17-safety-glazing-hazardous-locations 2026-10-14 https://contractorsclassroom.com/landing-images/c17-safety-glazing-hazardous-locations/en/og.jpg Safety Glazing: Is This Pane a Hazardous Location? - lesson diagram https://contractorsclassroom.com/learn/c17-glazing-glass-contractor-license-exam-prep/c17-sloped-glazing-load-combinations 2026-10-14 https://contractorsclassroom.com/landing-images/c17-sloped-glazing-load-combinations/en/og.jpg Sloped Glazing and Skylights: Load Combinations - lesson diagram https://contractorsclassroom.com/learn/c17-glazing-glass-contractor-license-exam-prep/c17-wind-load-check-glass-framing 2026-10-14 https://contractorsclassroom.com/landing-images/c17-wind-load-check-glass-framing/en/og.jpg Wind Load Check and Glass Framing Deflection Limits - lesson diagram https://contractorsclassroom.com/learn/c17-glazing-glass-contractor-license-exam-prep/c17-glass-guards-and-handrails 2026-10-14 https://contractorsclassroom.com/landing-images/c17-glass-guards-and-handrails/en/og.jpg Glass Guards and Handrails - lesson diagram https://contractorsclassroom.com/learn/c17-glazing-glass-contractor-license-exam-prep/c17-storefront-energy-area-weighted 2026-10-14 https://contractorsclassroom.com/landing-images/c17-storefront-energy-area-weighted/en/og.jpg Storefront Energy Compliance: Area-Weighted Ratings - lesson diagram https://contractorsclassroom.com/learn/c20-hvac-heating-air-conditioning-contractor-exam-prep/c20-airflow-fan-efficacy 2026-10-14 https://contractorsclassroom.com/landing-images/c20-airflow-fan-efficacy/en/og.jpg Airflow per Ton and Fan Efficacy: The Title 24 Verification Numbers - lesson diagram https://contractorsclassroom.com/learn/c20-hvac-heating-air-conditioning-contractor-exam-prep/c20-return-duct-filter-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c20-return-duct-filter-sizing/en/og.jpg Return Duct and Filter Sizing: Tables 150.0-B and 150.0-C, Equation 150.0-A - lesson diagram https://contractorsclassroom.com/learn/c20-hvac-heating-air-conditioning-contractor-exam-prep/c20-duct-leakage-targets 2026-10-14 https://contractorsclassroom.com/landing-images/c20-duct-leakage-targets/en/og.jpg Duct Leakage Targets: New Dwellings, Changeouts, and CMC Testing - lesson diagram https://contractorsclassroom.com/learn/c20-hvac-heating-air-conditioning-contractor-exam-prep/c20-condensate-drain-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c20-condensate-drain-sizing/en/og.jpg Condensate Drains: Pipe Size, Slope, and Overflow Protection - lesson diagram https://contractorsclassroom.com/learn/c20-hvac-heating-air-conditioning-contractor-exam-prep/c20-combustion-air-confined-space 2026-10-14 https://contractorsclassroom.com/landing-images/c20-combustion-air-confined-space/en/og.jpg Combustion Air for Furnaces in a Confined Space - lesson diagram https://contractorsclassroom.com/learn/c20-hvac-heating-air-conditioning-contractor-exam-prep/c20-dwelling-ventilation-rate 2026-10-14 https://contractorsclassroom.com/landing-images/c20-dwelling-ventilation-rate/en/og.jpg Whole-Dwelling Ventilation Rate (Energy Code Equation 150.0-B) - lesson diagram https://contractorsclassroom.com/learn/c21-building-moving-demolition-contractor-license-exam-prep/c21-moving-weight-takeoff 2026-10-14 https://contractorsclassroom.com/landing-images/c21-moving-weight-takeoff/en/og.jpg Estimating the Weight of a House You Are Going to Move - lesson diagram https://contractorsclassroom.com/learn/c21-building-moving-demolition-contractor-license-exam-prep/c21-jacks-cribbing-bearing 2026-10-14 https://contractorsclassroom.com/landing-images/c21-jacks-cribbing-bearing/en/og.jpg Jacks, Cribbing, and Ground Bearing Under a Lifted House - lesson diagram https://contractorsclassroom.com/learn/c21-building-moving-demolition-contractor-license-exam-prep/c21-house-move-height-width-clearance 2026-10-14 https://contractorsclassroom.com/landing-images/c21-house-move-height-width-clearance/en/og.jpg House Moves: Height, Width, and Route Clearance - lesson diagram https://contractorsclassroom.com/learn/c21-building-moving-demolition-contractor-license-exam-prep/c21-demolition-survey-sequence-openings 2026-10-14 https://contractorsclassroom.com/landing-images/c21-demolition-survey-sequence-openings/en/og.jpg Demolition Order of Work: Survey, Utilities, Sequence, and the 25 Percent Rule - lesson diagram https://contractorsclassroom.com/learn/c21-building-moving-demolition-contractor-license-exam-prep/c21-pedestrian-protection-drop-zones 2026-10-14 https://contractorsclassroom.com/landing-images/c21-pedestrian-protection-drop-zones/en/og.jpg Protecting the Public and Workers Below: Table 3306.1, Canopies, and Drop Zones - lesson diagram https://contractorsclassroom.com/learn/c21-building-moving-demolition-contractor-license-exam-prep/c21-debris-weight-diversion-loads 2026-10-14 https://contractorsclassroom.com/landing-images/c21-debris-weight-diversion-loads/en/og.jpg Demolition Debris: Tons, the 65 Percent Diversion Rule, and Truckloads - lesson diagram https://contractorsclassroom.com/learn/c22-asbestos-abatement-contractor-license-exam-prep/c22-negative-air-unit-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c22-negative-air-unit-sizing/en/og.jpg Sizing Negative Air Units: Enclosure Volume, ACH, and CFM - lesson diagram https://contractorsclassroom.com/learn/c22-asbestos-abatement-contractor-license-exam-prep/c22-pcm-air-sample-fiber-count 2026-10-14 https://contractorsclassroom.com/landing-images/c22-pcm-air-sample-fiber-count/en/og.jpg Air Sampling Math: Turning a PCM Fiber Count Into Fibers per cc - lesson diagram https://contractorsclassroom.com/learn/c22-asbestos-abatement-contractor-license-exam-prep/c22-respirator-selection-apf-muc 2026-10-14 https://contractorsclassroom.com/landing-images/c22-respirator-selection-apf-muc/en/og.jpg Respirator Selection: Class of Work, Exposure Level, and Maximum Use Concentration - lesson diagram https://contractorsclassroom.com/learn/c22-asbestos-abatement-contractor-license-exam-prep/c22-regulated-area-barriers-decon 2026-10-14 https://contractorsclassroom.com/landing-images/c22-regulated-area-barriers-decon/en/og.jpg Regulated Area Set-Up: Barriers, Signs, and the 25 Linear / 10 Square Foot Decon Trigger - lesson diagram https://contractorsclassroom.com/learn/c22-asbestos-abatement-contractor-license-exam-prep/c22-glovebag-removal-and-waste-bagging 2026-10-14 https://contractorsclassroom.com/landing-images/c22-glovebag-removal-and-waste-bagging/en/og.jpg Glovebag Removal on Pipe Insulation and Bagging the Waste - lesson diagram https://contractorsclassroom.com/learn/c23-ornamental-metal-contractor-license-exam-prep/c23-stair-stringer-layout 2026-10-14 https://contractorsclassroom.com/landing-images/c23-stair-stringer-layout/en/og.jpg Stair Stringer Layout: Riser Count, Tread Run, and Uniformity - lesson diagram https://contractorsclassroom.com/learn/c23-ornamental-metal-contractor-license-exam-prep/c23-guard-baluster-spacing 2026-10-14 https://contractorsclassroom.com/landing-images/c23-guard-baluster-spacing/en/og.jpg Guard Height and Baluster Spacing: The 4-Inch Sphere - lesson diagram https://contractorsclassroom.com/learn/c23-ornamental-metal-contractor-license-exam-prep/c23-handrail-profile-extensions 2026-10-14 https://contractorsclassroom.com/landing-images/c23-handrail-profile-extensions/en/og.jpg Handrail Profile, Clearance, and Extensions - lesson diagram https://contractorsclassroom.com/learn/c23-ornamental-metal-contractor-license-exam-prep/c23-accessible-ramp-rails 2026-10-14 https://contractorsclassroom.com/landing-images/c23-accessible-ramp-rails/en/og.jpg Accessible Ramp Rails: Rise, Landings, Extensions, and Edge Protection - lesson diagram https://contractorsclassroom.com/learn/c23-ornamental-metal-contractor-license-exam-prep/c23-guard-post-loads 2026-10-14 https://contractorsclassroom.com/landing-images/c23-guard-post-loads/en/og.jpg Guard and Handrail Loads: 200 lb, 50 plf, and the Post Base - lesson diagram https://contractorsclassroom.com/learn/c23-ornamental-metal-contractor-license-exam-prep/c23-caltrans-railing-galvanizing 2026-10-14 https://contractorsclassroom.com/landing-images/c23-caltrans-railing-galvanizing/en/og.jpg Caltrans Railing Steel: Galvanizing Schedule, Coating Check, and Tubular-Rail Fit - lesson diagram https://contractorsclassroom.com/learn/c27-landscaping-contractor-license-exam-prep/c27-water-budget-mawa-etwu 2026-10-14 https://contractorsclassroom.com/landing-images/c27-water-budget-mawa-etwu/en/og.jpg Landscape Water Budget: MAWA vs. ETWU - lesson diagram https://contractorsclassroom.com/learn/c27-landscaping-contractor-license-exam-prep/c27-compost-mulch-takeoff 2026-10-14 https://contractorsclassroom.com/landing-images/c27-compost-mulch-takeoff/en/og.jpg Soil Prep Takeoff: Compost and Mulch Quantities (MWELO) - lesson diagram https://contractorsclassroom.com/learn/c27-landscaping-contractor-license-exam-prep/c27-irrigation-design-limits 2026-10-14 https://contractorsclassroom.com/landing-images/c27-irrigation-design-limits/en/og.jpg Irrigation Design Checks: Setbacks, Narrow Strips, Slopes, and Meters - lesson diagram https://contractorsclassroom.com/learn/c27-landscaping-contractor-license-exam-prep/c27-irrigation-backflow-device 2026-10-14 https://contractorsclassroom.com/landing-images/c27-irrigation-backflow-device/en/og.jpg Backflow Protection for an Irrigation Supply (CPC Sec. 603) - lesson diagram https://contractorsclassroom.com/learn/c27-landscaping-contractor-license-exam-prep/c27-retaining-wall-permit-stability 2026-10-14 https://contractorsclassroom.com/landing-images/c27-retaining-wall-permit-stability/en/og.jpg Retaining Walls: The 4-Foot Permit Line and the 1.5 Safety Factor - lesson diagram https://contractorsclassroom.com/learn/c27-landscaping-contractor-license-exam-prep/c27-tree-work-near-power-lines 2026-10-14 https://contractorsclassroom.com/landing-images/c27-tree-work-near-power-lines/en/og.jpg Tree Work Near Power Lines: The 10-Foot Rule and Who May Cross It - lesson diagram https://contractorsclassroom.com/learn/c27-landscaping-contractor-license-exam-prep/c27-tree-felling-notch-cuts 2026-10-14 https://contractorsclassroom.com/landing-images/c27-tree-felling-notch-cuts/en/og.jpg Felling Cuts: Notch Depth, Back Cut, and Elevated-Work Rules - lesson diagram https://contractorsclassroom.com/learn/c28-locksmith-lock-security-contractor-license-exam-prep/c28-panic-hardware-rules 2026-10-14 https://contractorsclassroom.com/landing-images/c28-panic-hardware-rules/en/og.jpg Panic and Fire Exit Hardware: Where It Is Required and How to Size It - lesson diagram https://contractorsclassroom.com/learn/c28-locksmith-lock-security-contractor-license-exam-prep/c28-inactive-leaf-bolts 2026-10-14 https://contractorsclassroom.com/landing-images/c28-inactive-leaf-bolts/en/og.jpg Bolts on the Inactive Leaf of a Pair of Doors (Table 1010.2.4) - lesson diagram https://contractorsclassroom.com/learn/c28-locksmith-lock-security-contractor-license-exam-prep/c28-egress-door-lock-exceptions 2026-10-14 https://contractorsclassroom.com/landing-images/c28-egress-door-lock-exceptions/en/og.jpg When Can an Egress Door Be Locked? Key Locks, Dwelling Doors and Classrooms - lesson diagram https://contractorsclassroom.com/learn/c28-locksmith-lock-security-contractor-license-exam-prep/c28-electric-lock-egress-release 2026-10-14 https://contractorsclassroom.com/landing-images/c28-electric-lock-egress-release/en/og.jpg Electrically Locked Egress Doors: Hardware Release and Sensor Release - lesson diagram https://contractorsclassroom.com/learn/c28-locksmith-lock-security-contractor-license-exam-prep/c28-delayed-egress-locks 2026-10-14 https://contractorsclassroom.com/landing-images/c28-delayed-egress-locks/en/og.jpg Delayed Egress Locks: The 15-Second Rule, the Sign, and the Path Limit - lesson diagram https://contractorsclassroom.com/learn/c28-locksmith-lock-security-contractor-license-exam-prep/c28-hardware-height-force-closers 2026-10-14 https://contractorsclassroom.com/landing-images/c28-hardware-height-force-closers/en/og.jpg Door Hardware Height, Opening Force and Closer Timing - lesson diagram https://contractorsclassroom.com/learn/c28-locksmith-lock-security-contractor-license-exam-prep/c28-fire-door-hardware 2026-10-14 https://contractorsclassroom.com/landing-images/c28-fire-door-hardware/en/og.jpg Fire Door Hardware: Latching, Closers, Hold-Opens and Door Prep Limits (CBC 716) - lesson diagram https://contractorsclassroom.com/learn/c29-masonry-contractor-license-exam-prep/c29-fireplace-hearth-firebox 2026-10-14 https://contractorsclassroom.com/landing-images/c29-fireplace-hearth-firebox/en/og.jpg Masonry Fireplace: Hearth, Firebox Walls and Clearances - lesson diagram https://contractorsclassroom.com/learn/c29-masonry-contractor-license-exam-prep/c29-fireplace-flue-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c29-fireplace-flue-sizing/en/og.jpg Sizing the Flue for a Masonry Fireplace - lesson diagram https://contractorsclassroom.com/learn/c29-masonry-contractor-license-exam-prep/c29-chimney-height-clearances 2026-10-14 https://contractorsclassroom.com/landing-images/c29-chimney-height-clearances/en/og.jpg Chimney Height, Cricket, Spark Arrester and Clearances - lesson diagram https://contractorsclassroom.com/learn/c29-masonry-contractor-license-exam-prep/c29-chimney-seismic-reinforcement 2026-10-14 https://contractorsclassroom.com/landing-images/c29-chimney-seismic-reinforcement/en/og.jpg Chimney Seismic Steel, Ties and Strap Anchors - lesson diagram https://contractorsclassroom.com/learn/c29-masonry-contractor-license-exam-prep/c29-grouting-reinforced-masonry 2026-10-14 https://contractorsclassroom.com/landing-images/c29-grouting-reinforced-masonry/en/og.jpg Grouting Reinforced Masonry: Lifts, Pours and Cleanouts - lesson diagram https://contractorsclassroom.com/learn/c29-masonry-contractor-license-exam-prep/c29-mortar-types-batching 2026-10-14 https://contractorsclassroom.com/landing-images/c29-mortar-types-batching/en/og.jpg Mortar Types and Batching by Volume - lesson diagram https://contractorsclassroom.com/learn/c29-masonry-contractor-license-exam-prep/c29-anchored-veneer-ties-weeps 2026-10-14 https://contractorsclassroom.com/landing-images/c29-anchored-veneer-ties-weeps/en/og.jpg Anchored Masonry Veneer: Ties, Flashing and Weep Holes - lesson diagram https://contractorsclassroom.com/learn/c29-masonry-contractor-license-exam-prep/c29-masonry-wall-safety-zone 2026-10-14 https://contractorsclassroom.com/landing-images/c29-masonry-wall-safety-zone/en/og.jpg Masonry Wall Safety: Limited Access Zone, Bracing and Stacking - lesson diagram https://contractorsclassroom.com/learn/c31-traffic-control-contractor-license-exam-prep/c31-merging-taper-length-cone-count 2026-10-14 https://contractorsclassroom.com/landing-images/c31-merging-taper-length-cone-count/en/og.jpg Merging Taper Length and Cone Count - lesson diagram https://contractorsclassroom.com/learn/c31-traffic-control-contractor-license-exam-prep/c31-lane-closure-length-sign-spacing 2026-10-14 https://contractorsclassroom.com/landing-images/c31-lane-closure-length-sign-spacing/en/og.jpg Freeway Lane Closure Length: Signs, Taper and Buffer - lesson diagram https://contractorsclassroom.com/learn/c31-traffic-control-contractor-license-exam-prep/c31-flagger-station-stopping-distance 2026-10-14 https://contractorsclassroom.com/landing-images/c31-flagger-station-stopping-distance/en/og.jpg Flagger Station Placement and One-Lane, Two-Way Control - lesson diagram https://contractorsclassroom.com/learn/c31-traffic-control-contractor-license-exam-prep/c31-flagger-equipment-night-visibility 2026-10-14 https://contractorsclassroom.com/landing-images/c31-flagger-equipment-night-visibility/en/og.jpg Flagger Equipment, Signals and Night Visibility - lesson diagram https://contractorsclassroom.com/learn/c31-traffic-control-contractor-license-exam-prep/c31-pcms-arrow-board-setup 2026-10-14 https://contractorsclassroom.com/landing-images/c31-pcms-arrow-board-setup/en/og.jpg Portable Changeable Message Signs and Arrow Boards - lesson diagram https://contractorsclassroom.com/learn/c31-traffic-control-contractor-license-exam-prep/c31-channelizing-device-specifications 2026-10-14 https://contractorsclassroom.com/landing-images/c31-channelizing-device-specifications/en/og.jpg Cone, Drum and Channelizing Device Specifications - lesson diagram https://contractorsclassroom.com/learn/c32-parking-highway-improvement-contractor-license-exam-prep/c32-accessible-parking-count 2026-10-14 https://contractorsclassroom.com/landing-images/c32-accessible-parking-count/en/og.jpg Accessible Parking Count and Van Spaces - lesson diagram https://contractorsclassroom.com/learn/c32-parking-highway-improvement-contractor-license-exam-prep/c32-accessible-stall-layout 2026-10-14 https://contractorsclassroom.com/landing-images/c32-accessible-stall-layout/en/og.jpg Accessible Stall Layout, Slope and Markings - lesson diagram https://contractorsclassroom.com/learn/c32-parking-highway-improvement-contractor-license-exam-prep/c32-striping-paint-quantity 2026-10-14 https://contractorsclassroom.com/landing-images/c32-striping-paint-quantity/en/og.jpg Striping Paint Quantity: Linear Feet to Gallons - lesson diagram https://contractorsclassroom.com/learn/c32-parking-highway-improvement-contractor-license-exam-prep/c32-marking-material-application 2026-10-14 https://contractorsclassroom.com/landing-images/c32-marking-material-application/en/og.jpg Striping Materials: Temperature, Thickness and Acceptance Checks - lesson diagram https://contractorsclassroom.com/learn/c32-parking-highway-improvement-contractor-license-exam-prep/c32-removing-old-markings 2026-10-14 https://contractorsclassroom.com/landing-images/c32-removing-old-markings/en/og.jpg Removing Obsolete Markings: Limits and Pay Quantity - lesson diagram https://contractorsclassroom.com/learn/c32-parking-highway-improvement-contractor-license-exam-prep/c32-ev-charging-stall-counts 2026-10-14 https://contractorsclassroom.com/landing-images/c32-ev-charging-stall-counts/en/og.jpg EV Charging Stalls: Required Counts and Accessible Stalls - lesson diagram https://contractorsclassroom.com/learn/c32-parking-highway-improvement-contractor-license-exam-prep/c32-curb-colors-fire-lanes 2026-10-14 https://contractorsclassroom.com/landing-images/c32-curb-colors-fire-lanes/en/og.jpg Curb Colors and Fire Lane Clearances - lesson diagram https://contractorsclassroom.com/learn/c33-painting-contractor-license-exam-prep/c33-voc-regulatory-calculation 2026-10-14 https://contractorsclassroom.com/landing-images/c33-voc-regulatory-calculation/en/og.jpg VOC Content: Reading the CALGreen Coating Limits - lesson diagram https://contractorsclassroom.com/learn/c33-painting-contractor-license-exam-prep/c33-rrp-lead-safe-work 2026-10-14 https://contractorsclassroom.com/landing-images/c33-rrp-lead-safe-work/en/og.jpg Lead-Safe Painting: When the EPA RRP Rule Applies - lesson diagram https://contractorsclassroom.com/learn/c33-painting-contractor-license-exam-prep/c33-cal-osha-lead-trigger-tasks 2026-10-14 https://contractorsclassroom.com/landing-images/c33-cal-osha-lead-trigger-tasks/en/og.jpg Lead on the Job: Cal/OSHA PEL, Action Level and Trigger Tasks - lesson diagram https://contractorsclassroom.com/learn/c33-painting-contractor-license-exam-prep/c33-interior-finish-classes 2026-10-14 https://contractorsclassroom.com/landing-images/c33-interior-finish-classes/en/og.jpg Interior Finish Classes: What Can Go on the Wall - lesson diagram https://contractorsclassroom.com/learn/c33-painting-contractor-license-exam-prep/c33-steel-coating-weather-window 2026-10-14 https://contractorsclassroom.com/landing-images/c33-steel-coating-weather-window/en/og.jpg Weather Window: When You May Coat Steel (Caltrans §59-1.03B) - lesson diagram https://contractorsclassroom.com/learn/c33-painting-contractor-license-exam-prep/c33-caltrans-coat-film-build 2026-10-14 https://contractorsclassroom.com/landing-images/c33-caltrans-coat-film-build/en/og.jpg Film Build: Checking Each Coat and the Total Against the Spec - lesson diagram https://contractorsclassroom.com/learn/c34-pipeline-contractor-license-exam-prep/c34-trench-sloping-by-soil-type 2026-10-14 https://contractorsclassroom.com/landing-images/c34-trench-sloping-by-soil-type/en/og.jpg Sloping a Pipe Trench by Soil Type (Title 8 Appendix B) - lesson diagram https://contractorsclassroom.com/learn/c34-pipeline-contractor-license-exam-prep/c34-pipe-trench-width-bedding-backfill 2026-10-14 https://contractorsclassroom.com/landing-images/c34-pipe-trench-width-bedding-backfill/en/og.jpg Pipe Trench Width, Bedding, and Backfill Lifts - lesson diagram https://contractorsclassroom.com/learn/c34-pipeline-contractor-license-exam-prep/c34-thrust-block-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c34-thrust-block-sizing/en/og.jpg Thrust Block Sizing at Bends, Tees, and Dead Ends - lesson diagram https://contractorsclassroom.com/learn/c34-pipeline-contractor-license-exam-prep/c34-gravity-pipe-leakage-testing 2026-10-14 https://contractorsclassroom.com/landing-images/c34-gravity-pipe-leakage-testing/en/og.jpg Leakage Testing a Gravity Pipe: Exfiltration and Air Test - lesson diagram https://contractorsclassroom.com/learn/c34-pipeline-contractor-license-exam-prep/c34-cathodic-protection-gas-pipe-testing 2026-10-14 https://contractorsclassroom.com/landing-images/c34-cathodic-protection-gas-pipe-testing/en/og.jpg Cathodic Protection of Underground Steel Gas Pipe: Criteria and Test Schedule - lesson diagram https://contractorsclassroom.com/learn/c34-pipeline-contractor-license-exam-prep/c34-supply-line-pressure-test 2026-10-14 https://contractorsclassroom.com/landing-images/c34-supply-line-pressure-test/en/og.jpg Pressure Testing a Trenched Supply Line (Method A) - lesson diagram https://contractorsclassroom.com/learn/c35-lathing-plastering-contractor-license-exam-prep/c35-plaster-thickness-by-base 2026-10-14 https://contractorsclassroom.com/landing-images/c35-plaster-thickness-by-base/en/og.jpg Minimum Plaster Thickness by Base and the Cubic-Foot Takeoff - lesson diagram https://contractorsclassroom.com/learn/c35-lathing-plastering-contractor-license-exam-prep/c35-plaster-mix-proportions 2026-10-14 https://contractorsclassroom.com/landing-images/c35-plaster-mix-proportions/en/og.jpg Reading Plaster Mix Proportions by Coat - lesson diagram https://contractorsclassroom.com/learn/c35-lathing-plastering-contractor-license-exam-prep/c35-coat-count-and-cure-calendar 2026-10-14 https://contractorsclassroom.com/landing-images/c35-coat-count-and-cure-calendar/en/og.jpg Coat Counts and the Cure-Time Calendar - lesson diagram https://contractorsclassroom.com/learn/c35-lathing-plastering-contractor-license-exam-prep/c35-lath-fastening-and-weep-screed 2026-10-14 https://contractorsclassroom.com/landing-images/c35-lath-fastening-and-weep-screed/en/og.jpg Exterior Stucco: Lath Fastening and Weep Screed Layout - lesson diagram https://contractorsclassroom.com/learn/c35-lathing-plastering-contractor-license-exam-prep/c35-fire-rated-plaster-equivalents 2026-10-14 https://contractorsclassroom.com/landing-images/c35-fire-rated-plaster-equivalents/en/og.jpg Plaster in Fire-Rated Assemblies: Equivalents and Reinforcement - lesson diagram https://contractorsclassroom.com/learn/c35-lathing-plastering-contractor-license-exam-prep/c35-plaster-scaffold-and-mixer-safety 2026-10-14 https://contractorsclassroom.com/landing-images/c35-plaster-scaffold-and-mixer-safety/en/og.jpg Plasterers Scaffold and Mixer Guard Rules - lesson diagram https://contractorsclassroom.com/learn/c38-refrigeration-contractor-license-exam-prep/c38-rcl-room-charge-limit 2026-10-14 https://contractorsclassroom.com/landing-images/c38-rcl-room-charge-limit/en/og.jpg Refrigerant Charge Limit for a Room: RCL from CMC Table 1102.3 - lesson diagram https://contractorsclassroom.com/learn/c38-refrigeration-contractor-license-exam-prep/c38-machinery-room-emergency-ventilation 2026-10-14 https://contractorsclassroom.com/landing-images/c38-machinery-room-emergency-ventilation/en/og.jpg Machinery Room Triggers and Emergency Exhaust (CMC 1106) - lesson diagram https://contractorsclassroom.com/learn/c38-refrigeration-contractor-license-exam-prep/c38-relief-vent-back-pressure 2026-10-14 https://contractorsclassroom.com/landing-images/c38-relief-vent-back-pressure/en/og.jpg Relief Valve Vent Piping: Termination, Back Pressure and Length (CMC 1112) - lesson diagram https://contractorsclassroom.com/learn/c38-refrigeration-contractor-license-exam-prep/c38-field-pressure-test-declaration 2026-10-14 https://contractorsclassroom.com/landing-images/c38-field-pressure-test-declaration/en/og.jpg Field Pressure Test: Pressure, Test Gas and Declaration (CMC 1116) - lesson diagram https://contractorsclassroom.com/learn/c38-refrigeration-contractor-license-exam-prep/c38-calgreen-supermarket-leak-tight 2026-10-14 https://contractorsclassroom.com/landing-images/c38-calgreen-supermarket-leak-tight/en/og.jpg Supermarket Leak-Tight Installation: CALGreen 5.508.2 Pressure Test and Evacuation - lesson diagram https://contractorsclassroom.com/learn/c38-refrigeration-contractor-license-exam-prep/c38-warehouse-condenser-limits 2026-10-14 https://contractorsclassroom.com/landing-images/c38-warehouse-condenser-limits/en/og.jpg Refrigerated Warehouse Condensers: Design Condensing Temperature and Efficiency (Energy Code 120.6(a)) - lesson diagram https://contractorsclassroom.com/learn/c38-refrigeration-contractor-license-exam-prep/c38-warehouse-evaporator-efficiency 2026-10-14 https://contractorsclassroom.com/landing-images/c38-warehouse-evaporator-efficiency/en/og.jpg Warehouse Evaporators: Specific Efficiency, Fan Control and Static Pressure (Energy Code 120.6(a)3) - lesson diagram https://contractorsclassroom.com/learn/c38-refrigeration-contractor-license-exam-prep/c38-retail-store-heat-recovery 2026-10-14 https://contractorsclassroom.com/landing-images/c38-retail-store-heat-recovery/en/og.jpg Retail Food Store Refrigeration: Heat Recovery, Subcooling and Condenser Rules (Energy Code 120.6(b)) - lesson diagram https://contractorsclassroom.com/learn/c39-roofing-contractor-license-exam-prep/c39-roof-area-squares-bundles 2026-10-14 https://contractorsclassroom.com/landing-images/c39-roof-area-squares-bundles/en/og.jpg Roof Area, Squares, and Shingle Bundles - lesson diagram https://contractorsclassroom.com/learn/c39-roofing-contractor-license-exam-prep/c39-shingle-slope-underlayment 2026-10-14 https://contractorsclassroom.com/landing-images/c39-shingle-slope-underlayment/en/og.jpg Shingle Slope Limits and Underlayment Layers - lesson diagram https://contractorsclassroom.com/learn/c39-roofing-contractor-license-exam-prep/c39-attic-ventilation-nfa 2026-10-14 https://contractorsclassroom.com/landing-images/c39-attic-ventilation-nfa/en/og.jpg Attic Ventilation: Net Free Area (1/150 and 1/300) - lesson diagram https://contractorsclassroom.com/learn/c39-roofing-contractor-license-exam-prep/c39-low-slope-roofing-drainage 2026-10-14 https://contractorsclassroom.com/landing-images/c39-low-slope-roofing-drainage/en/og.jpg Low-Slope Roofing: Minimum Slope and Drainage - lesson diagram https://contractorsclassroom.com/learn/c39-roofing-contractor-license-exam-prep/c39-roofing-fall-protection-title8 2026-10-14 https://contractorsclassroom.com/landing-images/c39-roofing-fall-protection-title8/en/og.jpg Roofing Fall Protection: Title 8 Sections 1730 and 1731 - lesson diagram https://contractorsclassroom.com/learn/c39-roofing-contractor-license-exam-prep/c39-shingle-flashing-drip-edge 2026-10-14 https://contractorsclassroom.com/landing-images/c39-shingle-flashing-drip-edge/en/og.jpg Shingle Roof Flashing: Drip Edge, Step Flashing, Valleys, and Crickets - lesson diagram https://contractorsclassroom.com/learn/c42-sanitation-system-septic-contractor-license-exam-prep/c42-septic-tank-capacity 2026-10-14 https://contractorsclassroom.com/landing-images/c42-septic-tank-capacity/en/og.jpg Sizing a Septic Tank: Bedrooms, Flow, and Compartments - lesson diagram https://contractorsclassroom.com/learn/c42-sanitation-system-septic-contractor-license-exam-prep/c42-leach-field-area 2026-10-14 https://contractorsclassroom.com/landing-images/c42-leach-field-area/en/og.jpg Sizing a Leach Field: Soil, Square Feet, and Trench Length - lesson diagram https://contractorsclassroom.com/learn/c42-sanitation-system-septic-contractor-license-exam-prep/c42-seepage-pit-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c42-seepage-pit-sizing/en/og.jpg Sizing a Seepage Pit: Sidewall Area and Block Count - lesson diagram https://contractorsclassroom.com/learn/c42-sanitation-system-septic-contractor-license-exam-prep/c42-setback-distances 2026-10-14 https://contractorsclassroom.com/landing-images/c42-setback-distances/en/og.jpg Setback Distances: Reading Table H 101.8 - lesson diagram https://contractorsclassroom.com/learn/c42-sanitation-system-septic-contractor-license-exam-prep/c42-building-sewer-lateral 2026-10-14 https://contractorsclassroom.com/landing-images/c42-building-sewer-lateral/en/og.jpg Building Sewer Laterals: Fall, Size, Trench, and Cleanouts - lesson diagram https://contractorsclassroom.com/learn/c42-sanitation-system-septic-contractor-license-exam-prep/c42-septic-tank-entry-safety 2026-10-14 https://contractorsclassroom.com/landing-images/c42-septic-tank-entry-safety/en/og.jpg Entering a Septic Tank or Sewer: Confined-Space Atmosphere Rules - lesson diagram https://contractorsclassroom.com/learn/c43-sheet-metal-contractor-license-exam-prep/c43-gutter-leader-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c43-gutter-leader-sizing/en/og.jpg Sizing Gutters and Leaders: CPC Tables 1103.3 and 1103.1 - lesson diagram https://contractorsclassroom.com/learn/c43-sheet-metal-contractor-license-exam-prep/c43-product-conveying-duct-gauge 2026-10-14 https://contractorsclassroom.com/landing-images/c43-product-conveying-duct-gauge/en/og.jpg Product-Conveying Duct Gauge: CMC Tables 506.2(1) and 506.2(2) - lesson diagram https://contractorsclassroom.com/learn/c43-sheet-metal-contractor-license-exam-prep/c43-type-i-hood-size-exhaust 2026-10-14 https://contractorsclassroom.com/landing-images/c43-type-i-hood-size-exhaust/en/og.jpg Type I Kitchen Hoods: Metal, Overhang, and Net Exhaust (CMC 508) - lesson diagram https://contractorsclassroom.com/learn/c43-sheet-metal-contractor-license-exam-prep/c43-grease-duct-slope-clearance 2026-10-14 https://contractorsclassroom.com/landing-images/c43-grease-duct-slope-clearance/en/og.jpg Grease Duct: Gauge, Slope, Access, and Clearance (CMC 510 and 507.4) - lesson diagram https://contractorsclassroom.com/learn/c43-sheet-metal-contractor-license-exam-prep/c43-dryer-exhaust-duct-length 2026-10-14 https://contractorsclassroom.com/landing-images/c43-dryer-exhaust-duct-length/en/og.jpg Clothes Dryer Exhaust Duct: Length, Elbows, and Metal (CMC 504.4) - lesson diagram https://contractorsclassroom.com/learn/c43-sheet-metal-contractor-license-exam-prep/c43-metal-roof-panel-slope-materials 2026-10-14 https://contractorsclassroom.com/landing-images/c43-metal-roof-panel-slope-materials/en/og.jpg Metal Roof Panels: Minimum Slope, Materials, and Fasteners (CBC 1507.4) - lesson diagram https://contractorsclassroom.com/learn/c43-sheet-metal-contractor-license-exam-prep/c43-shear-guard-opening-table-g3 2026-10-14 https://contractorsclassroom.com/landing-images/c43-shear-guard-opening-table-g3/en/og.jpg Metal Shear Guarding: the 3/8-Inch Rule and Table G-3 (8 CCR 4227, 4186) - lesson diagram https://contractorsclassroom.com/learn/c43-sheet-metal-contractor-license-exam-prep/c43-press-brake-safety-distance 2026-10-14 https://contractorsclassroom.com/landing-images/c43-press-brake-safety-distance/en/og.jpg Press Brake Safeguarding: Safety Distance Ds = 63 x Ts (8 CCR 4214, 4208) - lesson diagram https://contractorsclassroom.com/learn/c45-sign-contractor-license-exam-prep/c45-sign-wind-load-force 2026-10-14 https://contractorsclassroom.com/landing-images/c45-sign-wind-load-force/en/og.jpg Wind Inputs and Footing Load for a Sign (CBC 1609, 1605.2) - lesson diagram https://contractorsclassroom.com/learn/c45-sign-contractor-license-exam-prep/c45-sign-pier-embedment-depth 2026-10-14 https://contractorsclassroom.com/landing-images/c45-sign-pier-embedment-depth/en/og.jpg Pier Embedment Depth for a Pole or Pylon Sign - lesson diagram https://contractorsclassroom.com/learn/c45-sign-contractor-license-exam-prep/c45-sign-lighting-power-energy 2026-10-14 https://contractorsclassroom.com/landing-images/c45-sign-lighting-power-energy/en/og.jpg Sign Lighting Power Limits (Energy Code Sec. 140.8) - lesson diagram https://contractorsclassroom.com/learn/c45-sign-contractor-license-exam-prep/c45-sign-disconnect-clearance-bonding 2026-10-14 https://contractorsclassroom.com/landing-images/c45-sign-disconnect-clearance-bonding/en/og.jpg Sign Disconnect, Height, and Line Clearance (Title 8 ESO) - lesson diagram https://contractorsclassroom.com/learn/c45-sign-contractor-license-exam-prep/c45-sign-accessible-tactile-11b 2026-10-14 https://contractorsclassroom.com/landing-images/c45-sign-accessible-tactile-11b/en/og.jpg Accessible Signs: Tactile Letters, Braille and Character Height (CBC 11B-703) - lesson diagram https://contractorsclassroom.com/learn/c45-sign-contractor-license-exam-prep/c45-sign-public-right-of-way 2026-10-14 https://contractorsclassroom.com/landing-images/c45-sign-public-right-of-way/en/og.jpg Signs Over the Public Right-of-Way (CBC Chapter 32) - lesson diagram https://contractorsclassroom.com/learn/c45-sign-contractor-license-exam-prep/c45-sign-plastic-face-limits 2026-10-14 https://contractorsclassroom.com/landing-images/c45-sign-plastic-face-limits/en/og.jpg Plastic Sign Faces and Mall Storefront Signs (CBC 402.6.4, 2606, 2611) - lesson diagram https://contractorsclassroom.com/learn/c46-solar-contractor-license-exam-prep/c46-sf-pv-size-equation 2026-10-14 https://contractorsclassroom.com/landing-images/c46-sf-pv-size-equation/en/og.jpg Single-Family PV Sizing: Equation 150.1-C - lesson diagram https://contractorsclassroom.com/learn/c46-solar-contractor-license-exam-prep/c46-nonres-pv-bess-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c46-nonres-pv-bess-sizing/en/og.jpg Commercial PV and Battery Sizing: Section 140.10 - lesson diagram https://contractorsclassroom.com/learn/c46-solar-contractor-license-exam-prep/c46-roof-pathways-setbacks 2026-10-14 https://contractorsclassroom.com/landing-images/c46-roof-pathways-setbacks/en/og.jpg Rooftop PV Fire Access: Pathways and Ridge Setbacks - lesson diagram https://contractorsclassroom.com/learn/c46-solar-contractor-license-exam-prep/c46-rapid-shutdown-labels 2026-10-14 https://contractorsclassroom.com/landing-images/c46-rapid-shutdown-labels/en/og.jpg Rapid Shutdown Labels and DC Conductor Rules - lesson diagram https://contractorsclassroom.com/learn/c46-solar-contractor-license-exam-prep/c46-home-battery-siting-bess-ready 2026-10-14 https://contractorsclassroom.com/landing-images/c46-home-battery-siting-bess-ready/en/og.jpg Home Battery Systems: BESS-Ready Panels and Where Batteries May Go - lesson diagram https://contractorsclassroom.com/learn/c46-solar-contractor-license-exam-prep/c46-roof-loads-under-pv-array 2026-10-14 https://contractorsclassroom.com/landing-images/c46-roof-loads-under-pv-array/en/og.jpg Roof Loads Under a PV Array: The Two Load Cases - lesson diagram https://contractorsclassroom.com/learn/c47-manufactured-housing-contractor-license-exam-prep/c47-soil-class-bearing 2026-10-14 https://contractorsclassroom.com/landing-images/c47-soil-class-bearing/en/og.jpg Soil Bearing Values from the Presumptive Load-Bearing Table - lesson diagram https://contractorsclassroom.com/learn/c47-manufactured-housing-contractor-license-exam-prep/c47-pier-footing-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c47-pier-footing-sizing/en/og.jpg Sizing Pier Footings from Pier Load and Soil Pressure - lesson diagram https://contractorsclassroom.com/learn/c47-manufactured-housing-contractor-license-exam-prep/c47-block-pier-height-clearance 2026-10-14 https://contractorsclassroom.com/landing-images/c47-block-pier-height-clearance/en/og.jpg Masonry Pier Height Limits and Wood-to-Ground Clearances - lesson diagram https://contractorsclassroom.com/learn/c47-manufactured-housing-contractor-license-exam-prep/c47-lot-drain-water-connections 2026-10-14 https://contractorsclassroom.com/landing-images/c47-lot-drain-water-connections/en/og.jpg Lot Drain Inlet, Drain Connector and Water Outlet - lesson diagram https://contractorsclassroom.com/learn/c47-manufactured-housing-contractor-license-exam-prep/c47-site-gas-supply 2026-10-14 https://contractorsclassroom.com/landing-images/c47-site-gas-supply/en/og.jpg Gas Supply at the Home Site: Demand, Burial, Valves and Air Test - lesson diagram https://contractorsclassroom.com/learn/c47-manufactured-housing-contractor-license-exam-prep/c47-crawlspace-ventilation-moisture 2026-10-14 https://contractorsclassroom.com/landing-images/c47-crawlspace-ventilation-moisture/en/og.jpg Crawlspace Ventilation, Vapor Retarder and Site Drainage - lesson diagram https://contractorsclassroom.com/learn/c50-reinforcing-steel-rebar-contractor-license-exam-prep/c50-bar-weight-takeoff 2026-10-14 https://contractorsclassroom.com/landing-images/c50-bar-weight-takeoff/en/og.jpg Rebar Weight Takeoff: Bar Sizes, Cover, and Tons - lesson diagram https://contractorsclassroom.com/learn/c50-reinforcing-steel-rebar-contractor-license-exam-prep/c50-standard-hooks-cut-length 2026-10-14 https://contractorsclassroom.com/landing-images/c50-standard-hooks-cut-length/en/og.jpg Standard Hooks and Bend Dimensions: What the Code Page Prints - lesson diagram https://contractorsclassroom.com/learn/c50-reinforcing-steel-rebar-contractor-license-exam-prep/c50-lap-splice-length 2026-10-14 https://contractorsclassroom.com/landing-images/c50-lap-splice-length/en/og.jpg Lap Splice Length: What Caltrans Section 52 and the CRC Print - lesson diagram https://contractorsclassroom.com/learn/c50-reinforcing-steel-rebar-contractor-license-exam-prep/c50-cover-clear-spacing-fit 2026-10-14 https://contractorsclassroom.com/landing-images/c50-cover-clear-spacing-fit/en/og.jpg Cover and Clear Spacing: Do the Bars Fit in the Member? - lesson diagram https://contractorsclassroom.com/learn/c50-reinforcing-steel-rebar-contractor-license-exam-prep/c50-footing-minimum-bars 2026-10-14 https://contractorsclassroom.com/landing-images/c50-footing-minimum-bars/en/og.jpg Minimum Bars in Footings and Plain Concrete Walls: Checking Bar Area - lesson diagram https://contractorsclassroom.com/learn/c50-reinforcing-steel-rebar-contractor-license-exam-prep/c50-rebar-impalement-protection 2026-10-14 https://contractorsclassroom.com/landing-images/c50-rebar-impalement-protection/en/og.jpg Rebar Impalement Protection: Covers, Troughs, and the 7-1/2 Foot Test - lesson diagram https://contractorsclassroom.com/learn/c50-reinforcing-steel-rebar-contractor-license-exam-prep/c50-rebar-assembly-safety 2026-10-14 https://contractorsclassroom.com/landing-images/c50-rebar-assembly-safety/en/og.jpg Reinforcing Steel Assemblies: Bracing, Hoisting, and Fall Protection - lesson diagram https://contractorsclassroom.com/learn/c51-structural-steel-contractor-license-exam-prep/c51-reading-shape-designations 2026-10-14 https://contractorsclassroom.com/landing-images/c51-reading-shape-designations/en/og.jpg Reading Steel Callouts, Substitutions, and Material Identity - lesson diagram https://contractorsclassroom.com/learn/c51-structural-steel-contractor-license-exam-prep/c51-steel-weight-takeoff 2026-10-14 https://contractorsclassroom.com/landing-images/c51-steel-weight-takeoff/en/og.jpg Steel Weight Takeoff: Pounds per Foot, Plates, Welds, and Tons - lesson diagram https://contractorsclassroom.com/learn/c51-structural-steel-contractor-license-exam-prep/c51-high-strength-bolt-tightening 2026-10-14 https://contractorsclassroom.com/landing-images/c51-high-strength-bolt-tightening/en/og.jpg High-Strength Bolts: Assemblies, Holes, and Caltrans Verification Testing - lesson diagram https://contractorsclassroom.com/learn/c51-structural-steel-contractor-license-exam-prep/c51-sling-angle-multiple-lift 2026-10-14 https://contractorsclassroom.com/landing-images/c51-sling-angle-multiple-lift/en/og.jpg Sling Angles and the Multiple-Lift Rules - lesson diagram https://contractorsclassroom.com/learn/c51-structural-steel-contractor-license-exam-prep/c51-column-anchorage-and-two-bolt-rule 2026-10-14 https://contractorsclassroom.com/landing-images/c51-column-anchorage-and-two-bolt-rule/en/og.jpg Column Anchorage, Two-Bolt Release, and Double Connections - lesson diagram https://contractorsclassroom.com/learn/c51-structural-steel-contractor-license-exam-prep/c51-skeleton-steel-fall-protection 2026-10-14 https://contractorsclassroom.com/landing-images/c51-skeleton-steel-fall-protection/en/og.jpg Fall Protection on Skeleton Steel: Connector Heights, Perimeter Cable, and the CDZ - lesson diagram https://contractorsclassroom.com/learn/c53-swimming-pool-contractor-license-exam-prep/c53-turnover-flow-rate-pump-head 2026-10-14 https://contractorsclassroom.com/landing-images/c53-turnover-flow-rate-pump-head/en/og.jpg Turnover Time, Flow Rate, and Pump Head - lesson diagram https://contractorsclassroom.com/learn/c53-swimming-pool-contractor-license-exam-prep/c53-filter-area-backwash-pump-head 2026-10-14 https://contractorsclassroom.com/landing-images/c53-filter-area-backwash-pump-head/en/og.jpg Sizing a Filter: Flow Rate per Square Foot - lesson diagram https://contractorsclassroom.com/learn/c53-swimming-pool-contractor-license-exam-prep/c53-suction-outlets-entrapment-velocity 2026-10-14 https://contractorsclassroom.com/landing-images/c53-suction-outlets-entrapment-velocity/en/og.jpg Suction Outlets and Entrapment: Two Drains and the Velocity Limits - lesson diagram https://contractorsclassroom.com/learn/c53-swimming-pool-contractor-license-exam-prep/c53-floor-slope-depth-line-markers 2026-10-14 https://contractorsclassroom.com/landing-images/c53-floor-slope-depth-line-markers/en/og.jpg Pool Floor Slope, the 4-1/2 Foot Line, and Depth Markers - lesson diagram https://contractorsclassroom.com/learn/c53-swimming-pool-contractor-license-exam-prep/c53-deck-slope-coping-handholds 2026-10-14 https://contractorsclassroom.com/landing-images/c53-deck-slope-coping-handholds/en/og.jpg Pool Deck Slope, Coping, and the 9-Inch Handhold - lesson diagram https://contractorsclassroom.com/learn/c53-swimming-pool-contractor-license-exam-prep/c53-pool-heater-energy-code-solar-sizing 2026-10-14 https://contractorsclassroom.com/landing-images/c53-pool-heater-energy-code-solar-sizing/en/og.jpg Pool Heaters and Solar: Energy Code Checklist and Collector Sizing - lesson diagram https://contractorsclassroom.com/learn/c53-swimming-pool-contractor-license-exam-prep/c53-pool-electrical-clearances-8ccr-article-79 2026-10-14 https://contractorsclassroom.com/landing-images/c53-pool-electrical-clearances-8ccr-article-79/en/og.jpg Pool Electrical Clearances: Receptacles, Lights, and Cords - lesson diagram https://contractorsclassroom.com/learn/c53-swimming-pool-contractor-license-exam-prep/c53-two-of-seven-drowning-prevention-features 2026-10-14 https://contractorsclassroom.com/landing-images/c53-two-of-seven-drowning-prevention-features/en/og.jpg New Residential Pools: Choosing Two of the Seven Safety Features - lesson diagram https://contractorsclassroom.com/learn/c54-tile-contractor-license-exam-prep/c54-tile-layout-balanced-cuts 2026-10-14 https://contractorsclassroom.com/landing-images/c54-tile-layout-balanced-cuts/en/og.jpg Tile Layout: Centering and Balanced Cuts (Practice) - lesson diagram https://contractorsclassroom.com/learn/c54-tile-contractor-license-exam-prep/c54-floor-deflection-tile 2026-10-14 https://contractorsclassroom.com/landing-images/c54-floor-deflection-tile/en/og.jpg Floor Framing Under Tile: L/360 and the Joist Span Table - lesson diagram https://contractorsclassroom.com/learn/c54-tile-contractor-license-exam-prep/c54-shower-receptor-slope-curb 2026-10-14 https://contractorsclassroom.com/landing-images/c54-shower-receptor-slope-curb/en/og.jpg Shower Receptor: Slope, Curb, Lining Height and Flood Test - lesson diagram https://contractorsclassroom.com/learn/c54-tile-contractor-license-exam-prep/c54-backer-board-wet-wall-heights 2026-10-14 https://contractorsclassroom.com/landing-images/c54-backer-board-wet-wall-heights/en/og.jpg Backer Board and Wet-Wall Tile Heights - 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