Section 1907A
California Building Code (Title 24, Part 2) · 2022 edition · updated 2026-09-12 · California
Italicized text is a California amendment to the model code, as printed in the official publication.
MINIMUM SLAB PROVISIONS
1907 A .1 General. The thickness of concrete floor slabs supported directly on the ground shall be not less than 3 1 /2 inches (89 mm). A 6-mil (0.006 inch; 0.15 mm) polyethylene vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the base course or subgrade and the concrete floor slab, or other approved equivalent methods or materials shall be used to retard vapor transmission through the floor slab.
Exception: A vapor retarder is not required:
For detached structures accessory to occupancies in Group R-3, such as garages, utility buildings or other unheated facilities.
For unheated storage rooms having an area of less than 70 square feet (6.5 m 2 ) and carports attached to occupancies in Group R-3.
For buildings of other occupancies where migration of moisture through the slab from below will not be
19A-8 2022 CALIFORNIA BUILDING CODE
Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. Any unauthorized reproduction or distribution is a violation of the federal copyright act and the license agreement, and subject to civil and criminal penalties thereunder.
concrete. Cementitious materials without Certification of Com- pliance shall not be used.
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Ask AI about this code▸Contents — California Building Code (Title 24, Part 2)
- Chapter 2 — DEFINITIONS AND ABBREVIATIONS
- Appendix G — FLOOD-RESISTANT
- Appendix L — EARTHQUAKE RECORDING
- Appendix M — TSUNAMI-GENERATED
- Appendix N — REPLICABLE
- Appendix O — PERFORMANCE-BASED
- Chapter 1 — SCOPE AND ADMINISTRATION
- Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
- Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
- Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
- Chapter 6 — TYPES OF CONSTRUCTION
- Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
- Chapter 7A — MATERIALS AND CONSTRUCTION
- Chapter 8 — INTERIOR FINISHES
- Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
- Chapter 10 — MEANS OF EGRESS
- Chapter 11A — HOUSING ACCESSIBILITY
- Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
- Chapter 12 — INTERIOR ENVIRONMENT
- Chapter 14 — EXTERIOR WALLS
- Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
- Chapter 16 — STRUCTURAL DESIGN
- Chapter 16A — STRUCTURAL DESIGN
- Chapter 17 — SPECIAL INSPECTIONS AND TESTS
- Chapter 18 — SOILS AND FOUNDATIONS
▸Chapter 19 — CONCRETE
- Chapter 20 — ALUMINUM
- Chapter 21 — MASONRY
- Chapter 22 — STEEL
- Chapter 23 — WOOD
- Chapter 24 — GLASS AND GLAZING
- Chapter 25 — GYPSUM BOARD, GYPSUM PANEL PRODUCTS AND PLASTER
- Chapter 26 — PLASTIC
- Chapter 27 — ELECTRICAL
- Chapter 28 — MECHANICAL SYSTEMS
- Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
- Chapter 31 — SPECIAL CONSTRUCTION
- Chapter 31B — PUBLIC POOLS
- Chapter 31C — RADIATION
- Chapter 31D — FOOD ESTABLISHMENTS
- Chapter 31F — MARINE OIL TERMINALS
- Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
- Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
- Chapter 35 — REFERENCED STANDARDS
- Appendix A — EMPLOYEE QUALIFICATIONS
- Appendix B — BOARD OF APPEALS
- Appendix C — GROUP U – AGRICULTURAL BUILDINGS
- Appendix D — FIRE DISTRICTS
- Appendix F — RODENTPROOFING
- Appendix H — SIGNS
- Appendix I — PATIO COVERS
- Appendix J — GRADING
- Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES
- Appendix P — EMERGENCY HOUSING