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Chapter 26 — PLASTIC

Section 2604

California Building Code (Title 24, Part 2) · 2019 edition · updated 2026-09-12 · California

Italicized text is a California amendment to the model code, as printed in the official publication.

2604.1 General.

Plastic materials installed as interior finish or trim shall comply with Chapter 8. Foam plastics shall only be installed as interior finish where approved in accordance with the special provisions of Section 2603.9. Foam plastics that are used as interior finish shall meet the flame spread and smoke-developed index requirements for interior finish in accordance with Chapter 8. Foam plastics installed as interior trim shall comply with Section 2604.2.

2604.1.1 Plenums. Foam plastics installed in plenums as interior wall or ceiling finish shall comply with Section 2603.7. Foam plastics installed in plenums as interior trim shall comply with Sections 2604.2 and 2603.7.

[F] 2604.2 Interior trim. Foam plastic used as interior trim shall comply with Sections 2604.2.1 through 2604.2.4.

[F] 2604.2.1 Density. The minimum density of the interior trim shall be 20 pcf (320 kg/m 3 ).

TABLE 2603.13.2 FURRING MINIMUM FASTENING REQUIREMENTS FOR APPLICATION OVER FOAM PLASTIC SHEATHING TO SUPPORT CLADDING WEIGHT a, b

FURRING MATERIAL FRAMING MEMBER FASTENER TYPE AND MINIMUM SIZE MINIMUM PENETRATION INTO WALL FRAMING (INCHES) FASTENER SPACING IN FURRING (INCHES) MAXIMUM THICKNESS OF FOAM SHEATHINGd (INCHES)
FURRING MATERIAL FRAMING MEMBER FASTENER TYPE
AND MINIMUM SIZE		 MINIMUM PENETRATION INTO
WALL FRAMING (INCHES)		 FASTENER SPACING IN
FURRING (INCHES)		 16″** o.c. furringe** 16″** o.c. furringe** 16″** o.c. furringe** 16″** o.c. furringe** 24″** o.c. furringe** 24″** o.c. furringe** 24″** o.c. furringe** 24″** o.c. furringe**
FURRING MATERIAL FRAMING MEMBER FASTENER TYPE
AND MINIMUM SIZE		 MINIMUM PENETRATION INTO
WALL FRAMING (INCHES)		 FASTENER SPACING IN
FURRING (INCHES)		 Siding weight: Siding weight: Siding weight: Siding weight: Siding weight: Siding weight: Siding weight: Siding weight:
FURRING MATERIAL FRAMING MEMBER FASTENER TYPE
AND MINIMUM SIZE		 MINIMUM PENETRATION INTO
WALL FRAMING (INCHES)		 FASTENER SPACING IN
FURRING (INCHES)		 3 psf 11 psf 18 psf 25 psf 3 psf 11 psf 18 psf 25 psf
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 0.131"
diameter
nail		 11/4 8 4.00 2.45 1.45 0.95 4.00 1.60 0.85 DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 0.131"
diameter
nail		 11/4 12 4.00 1.60 0.85 DR 4.00 0.95 DR DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 0.131"
diameter
nail		 11/4 16 4.00 1.10 DR DR 3.05 0.60 DR DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 0.162"
diameter
nail		 11/4 8 4.00 4.00 2.45 1.60 4.00 2.75 1.45 0.85
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 0.162"
diameter
nail		 11/4 12 4.00 2.75 1.45 0.85 4.00 1.65 0.75 DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 0.162"
diameter
nail		 11/4 16 4.00 1.90 0.95 DR 4.00 1.05 DR DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 No. 10
wood
screw		 1 12 4.00 2.30 1.20 0.70 4.00 1.40 0.60 DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 No. 10
wood
screw		 1 16 4.00 1.65 0.75 DR 4.00 0.90 DR DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 No. 10
wood
screw		 1 24 4.00 0.90 DR DR 2.85 DR DR DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 1/4" lag
screw		 11/2 12 4.00 2.65 1.50 0.90 4.00 1.65 0.80 DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 1/4" lag
screw		 11/2 16 4.00 1.95 0.95 0.50 4.00 1.10 DR DR
Minimum
1x Wood
Furringc		 Minimum
2x Wood
Stud		 1/4" lag
screw		 11/2 24 4.00 1.10 DR DR 3.25 0.50 DR DR

For SI: 1 inch = 25.4 mm, 1 pound per square foot (psf) = 0.0479 kPa, 1 pound per square inch = 0.00689 MPa.

DR = Design Required, o.c. = on center. a. Wood framing and furring shall be spruce-pine-fir or any wood species with a specific gravity of 0.42 or greater in accordance with ANSI/AWC NDS. b. Nail fasteners shall comply with ASTM F1667, except nail length shall be permitted to exceed ASTM F1667 standard lengths. c. Where the required cladding fastener penetration into wood material exceeds 3 /4 inch and is not more than 1 1 /2 inches, a minimum 2-inch nominal wood furring

or an approved design shall be used. d. Foam sheathing shall have a minimum compressive strength of 15 psi in accordance with ASTM C578 or ASTM C1289. e. Furring shall be spaced not greater than 24 inches on center in a vertical or horizontal orientation. In a vertical orientation, furring shall be located over wall

studs and attached with the required fastener spacing. In a horizontal orientation, the indicated 8-inch and 12-inch fastener spacing in furring shall be achieved by use of two fasteners into studs at 16 inches and 24 inches on center, respectively.

412 2019 CALIFORNIA BUILDING CODE

Copyright © 2019 ICC. ALL RIGHTS RESERVED. Accessed by Kevin Day (kevin.day@dgs.ca.gov), (California Building Standards Commission) Order Number #100735044 on Jul 24, 2019 03:54 PM (PDT) pursuant to License Agreement with ICC. No further reproduction or distribution authorized. Single user only, copying and networking prohibited. 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.

100735044

[F] 2604.2.2 Thickness. The maximum thickness of the interior trim shall be 1 /2 inch (12.7 mm) and the maximum width shall be 8 inches (204 mm).

[F] 2604.2.3 Area limitation. The interior trim shall not constitute more than 10 percent of the specific wall or ceiling areas to which it is attached.

[F] 2604.2.4 Flame spread. The flame spread index shall not exceed 75 where tested in accordance with ASTM E84 or UL 723. The smoke-developed index shall not be limited.

Exception: Where the interior trim material has been tested as an interior finish in accordance with NFPA 286 and complies with the acceptance criteria in Section 803.1.1.1, it shall not be required to be tested for flame spread index in accordance with ASTM E84 or UL 723.

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▸Contents — California Building Code (Title 24, Part 2)
California Building Code (Title 24, Part 2)
  1. Chapter 2 — DEFINITIONS AND ABBREVIATIONS
  2. Appendix G — FLOOD-RESISTANT
  3. Appendix L — EARTHQUAKE RECORDING
  4. Appendix M — TSUNAMI-GENERATED
  5. Chapter 1 — SCOPE AND ADMINISTRATION
  6. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  7. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED
  8. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  9. Chapter 6 — TYPES OF CONSTRUCTION
  10. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  11. Chapter 7A — MATERIALS AND CONSTRUCTION
  12. Chapter 8 — INTERIOR FINISHES
  13. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  14. Chapter 10 — MEANS OF EGRESS
  15. Chapter 11A — HOUSING ACCESSIBILITY
  16. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  17. Chapter 12 — INTERIOR ENVIRONMENT
  18. Chapter 14 — EXTERIOR WALLS
  19. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  20. Chapter 16 — STRUCTURAL DESIGN
  21. Chapter 16A — STRUCTURAL DESIGN
  22. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  23. Chapter 18 — SOILS AND FOUNDATIONS
  24. Chapter 19 — CONCRETE
  25. Chapter 20 — ALUMINUM
  26. Chapter 21 — MASONRY
  27. Chapter 22 — STEEL
  28. Chapter 23 — WOOD
  29. Chapter 24 — GLASS AND GLAZING
  30. Chapter 25 — GYPSUM BOARD, GYPSUM PANEL PRODUCTS AND PLASTER
  31. ▸Chapter 26 — PLASTIC
    Overview
    1. Section 2601
    2. Section 2602
    3. Section 2603
    4. Section 2604
    5. Section 2605
    6. Section 2606
    7. Section 2607
    8. Section 2608
    9. Section 2609
    10. Section 2610
    11. Section 2613
    12. Section 2611
    13. Section 2612
    14. Section 2614
  32. Chapter 27 — ELECTRICAL
  33. Chapter 28 — MECHANICAL SYSTEMS
  34. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  35. Chapter 31 — SPECIAL CONSTRUCTION
  36. Chapter 31B — PUBLIC POOLS
  37. Chapter 31C — RADIATION
  38. Chapter 31D — FOOD ESTABLISHMENTS
  39. Chapter 31F — MARINE OIL TERMINALS
  40. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  41. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  42. Chapter 35 — REFERENCED STANDARDS
  43. Appendix A — EMPLOYEE QUALIFICATIONS
  44. Appendix B — BOARD OF APPEALS
  45. Appendix C — GROUP U – AGRICULTURAL BUILDINGS
  46. Appendix D — FIRE DISTRICTS
  47. Appendix F — RODENTPROOFING
  48. Appendix H — SIGNS
  49. Appendix I — PATIO COVERS
  50. Appendix J — GRADING
  51. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES
  52. Appendix N — REPLICABLE BUILDINGS
  53. Appendix O — EMERGENCY HOUSING

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