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Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

Section 1504 — PERFORMANCE REQUIREMENTS

2025 California Building Code (Title 24, Part 2) · 2025 edition · updated 2026-07-29 · California

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

1504.1 Wind resistance of roofs.

Roof decks and roof coverings shall be designed in accordance with Section 1504.

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

1504.2 Wind resistance of asphalt shingles.

Asphalt shingles shall be tested in accordance with ASTM D7158. Asphalt shingles shall meet the classification requirements of Table 1504.2 for the appropriate maximum basic wind speed. Asphalt shingle packaging shall bear a label to indicate compliance with ASTM D7158 and the required classification in Table 1504.2.

Exception: Asphalt shingles not included in the scope of ASTM D7158 shall be tested and labeled in accordance with ASTM D3161. Asphalt shingle packaging shall bear a label to indicate compliance with ASTM D3161 and the required classification in Table 1504.2.

TABLE 1504.2—CLASSIFICATION OF STEEP SLOPE ROOF SHINGLES TESTED IN ACCORDANCE WITH ASTM D3161 OR D7158

MAXIMUM BASIC WIND SPEED,****V, FROM
FIGURES 1609.3(1)–(4) OR ASCE 7 (mph)		 MAXIMUM ALLOWABLE STRESS DESIGN WIND
SPEED,****Vasd, FROM Table 1609.3.1 (mph)		 **ASTM D7158a **
CLASSIFICATION		 ASTM D3161 or
UL 7103 CLASSIFICATION
110 85 D, G or H A, D or F
116 90 D, G or H A, D or F
129 100 G or H A, D or F
142 110 G or H F
155 120 G or H F
168 130 H F
181 140 H F
194 150 H F
For SI: 1 foot = 304.8 mm, 1 mph = 0.447 m/s.
a. The standard calculations contained in ASTM D7158 assume Exposure Category B or C and building height of 60 feet or less. Additional calculations are required for condi-
tions outside of these assumptions.

1504.3 Wind resistance of clay and concrete tile.

Wind loads on clay and concrete tile roof coverings shall be in accordance with Section 1609.6.

1504.3.1 Testing. Testing of concrete and clay roof tiles shall be in accordance with Sections 1504.3.1.1, 1504.3.1.2 and 1504.3.1.3.

1504.3.1.1 Overturning resistance. Concrete and clay roof tiles shall be tested to determine their resistance to overturning due to wind in accordance with Chapter 15 and either SBCCI SSTD 11 or ASTM C1568.

1504.3.1.2 Wind tunnel testing. Where concrete and clay roof tiles do not satisfy the limitations in Chapter 16 for rigid tile, a wind tunnel test shall be used to determine the wind characteristics of the concrete or clay tile roof covering in accordance with Chapter 15 and either SBCCI SSTD 11 or ASTM C1569.

1504.3.1.3 Air permeability testing. The lift coefficient for concrete and clay tile shall be 0.2 or shall be determined in accordance with SBCCI SSTD 11 or ASTM C1570.

1504.4 Wind resistance of nonballasted roofs.

Roof coverings installed on roofs in accordance with Section 1507 that are mechanically attached or adhered to the roof deck shall be designed to resist the design wind load pressures for components and cladding in accordance with Section 1609.6.2. The wind load on the roof covering shall be permitted to be determined using allowable stress design.

1504.4.1 Other roof systems. Built-up, modified bitumen, fully adhered or mechanically attached single-ply roof systems, metal panel roof systems applied to a solid or closely fitted deck and other types of membrane roof coverings shall be tested in accordance with FM 4474, UL 580 or UL 1897.

1504.4.2 Structural metal panel roof systems. Where the metal roof panel functions as the roof deck and roof covering and it provides both weather protection and support for loads, the structural metal panel roof system shall comply with this section. Structural standing-seam metal panel roof systems shall be tested in accordance with ASTM E1592 or FM 4474. Structural through-fastened metal panel roof systems shall be tested in accordance with ASTM E1592, FM 4474 or UL 580.

Exceptions:

  1. Metal roofs constructed of cold-formed steel shall be permitted to be designed and tested in accordance with the applicable referenced structural design standard in Section 2204.1.
  2. Metal roofs constructed of aluminum shall be permitted to be designed and tested in accordance with the applicable referenced structural design standard in Section 2002.1.

1504.4.3 Metal roof shingles. Metal roof shingles applied to a solid or closely fitted deck shall be tested in accordance with ASTM D3161, FM 4474, UL 580 or UL 1897. Metal roof shingles tested in accordance with ASTM D3161 shall meet the classification requirements of Table 1504.2 for the appropriate maximum basic wind speed and the metal shingle packaging shall bear a label to indicate compliance with ASTM D3161 and the required classification in Table 1504.2.

1504.4.4 Slate shingles. Slate shingles shall be tested in accordance with ASTM D3161. Slate packaging shall bear a label indicating compliance with ASTM D3161 and the required classification in Table 1504.2.

1504.5 Ballasted low-slope single-ply roof systems.

Ballasted low-slope single-ply roof system coverings installed in accordance with Section 1507.12 shall be designed in accordance with ANSI/SPRI RP-4.

1504.6 Edge systems for low-slope roofs.

Metal edge systems, except gutters and counterflashing, installed on built-up, modified bitumen and single-ply roof systems on a low-slope roof shall be designed and installed for wind loads in accordance with Chapter 16

15-4 2025 CALIFORNIA BUILDING CODE

on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.

ROOF ASSEMBLIES AND ROOFTOP STRUCTURES

and tested for resistance in accordance with Test Methods RE-1, RE-2 and RE-3 of ANSI/SPRI ES-1, except basic wind speed, V, shall be determined from Figures 1609.3(1)through 1609.3(4), as applicable.

1504.6.1 Gutter securement for low-slope roofs. Gutters that are used to secure the perimeter edge of the roof membrane on low-slope built-up, modified bitumen, and single-ply roofs, shall be designed, constructed and installed to resist wind loads in accordance with Section 1609 and shall be tested in accordance with Test Methods G-1 and G-2 of SPRI GT-1.

1504.7 Impact resistance.

Roof coverings installed on low-slope roofs in accordance with Section 1507 shall resist impact damage based on the results of tests conducted in accordance with ASTM D3746, ASTM D4272 or the “Resistance to Foot Traffic Test” in FM 4470.

1504.8 Wind resistance of aggregate-surfaced roofs.

Parapets shall be provided for aggregate surfaced roofs and shall comply with Table 1504.8. Such parapets shall be provided on the perimeter of the roof at all exterior sides except where an adjacent wall extends above the roof to a height at least equivalent to that required for the parapet. For roofs with differing surface elevations due to slope or sections at different elevations, the minimum parapet height shall be determined based on each roof surface elevation, and at no point shall the parapet height be less than that required by Table 1504.8.

Exception: Ballasted single-ply roof coverings shall be designed and installed in accordance with Section 1504.5.

TABLE 1504.8—MINIMUM REQUIRED PARAPET HEIGHT (INCHES) FOR AGGREGATE SURFACED ROOFSa, b, c, d, e

AGGREGATE
SIZE		 MEAN
ROOF
HEIGHT
(feet)		 WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH) WIND EXPOSURE AND BASIC WIND SPEED,****V (MPH)
AGGREGATE
SIZE		 MEAN
ROOF
HEIGHT
(feet)		 Exposure B Exposure B Exposure B Exposure B Exposure B Exposure B Exposure B Exposure B Exposure B Exposure Cf Exposure Cf Exposure Cf Exposure Cf Exposure Cf Exposure Cf Exposure Cf Exposure Cf Exposure Cf
AGGREGATE
SIZE		 MEAN
ROOF
HEIGHT
(feet)		 ≤ 95 100 105 110 115 120 130 140 150 ≤ 95 100 105 110 115 120 130 140 150
ASTM D1863
(No. 7 or No.
67)		 15 2 2 2 2 12 12 16 20 24 2 13 15 18 20 23 27 32 37
ASTM D1863
(No. 7 or No.
67)		 20 2 2 2 2 12 14 18 22 26 12 15 17 19 22 24 29 34 39
ASTM D1863
(No. 7 or No.
67)		 30 2 2 2 13 15 17 21 25 30 14 17 19 22 24 27 32 37 42
ASTM D1863
(No. 7 or No.
67)		 50 12 12 14 16 18 21 25 30 35 17 19 22 25 28 30 36 41 47
ASTM D1863
(No. 7 or No.
67)		 100 14 16 19 21 24 27 32 37 42 21 24 26 29 32 35 41 47 53
ASTM D1863
(No. 7 or No.
67)		 150 17 19 22 25 27 30 36 41 46 23 26 29 32 35 38 44 50 56
ASTM D1863
(No. 6)		 15 2 2 2 2 12 12 12 15 18 2 2 2 13 15 17 22 26 30
ASTM D1863
(No. 6)		 20 2 2 2 2 12 12 13 17 21 2 2 12 15 17 19 23 28 32
ASTM D1863
(No. 6)		 30 2 2 2 2 12 12 16 20 24 2 12 14 17 19 21 26 31 35
ASTM D1863
(No. 6)		 50 12 12 12 12 14 16 20 24 28 12 15 17 19 22 24 29 34 39
ASTM D1863
(No. 6)		 100 12 12 14 16 19 21 26 30 35 16 18 21 24 26 29 34 39 45
ASTM D1863
(No. 6)		 150 12 14 17 19 22 24 29 34 39 18 21 23 26 29 32 37 43 48

For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 mile per hour = 0.447 m/s.
a. Parapet height is measured vertically from the top surface of the coping down to the surface of the roof covering in the field of the roof adjacent to the parapet and outbound
of any cant strip.
b. Interpolation shall be permitted for wind speed, mean roof height and parapet height. Extrapolation is not permitted.
c. Basic wind speed,V, and wind exposure shall be determined in accordance with Section 1609.
d. Where the minimum required parapet height is indicated to be 2 inches (51 mm), a gravel stop shall be permitted and shall extend not less than 2 inches (51 mm) from the roof
surface and not less than the height of the aggregate.
e. The tabulated values apply only to conditions where the topographic factor (Kzt) determined in accordance with Chapter 26 of ASCE 7 is 1.0 or where_Kzt_ is incorporated in the
basic wind speed in Section 1609.
f. For Exposure D, add 8 inches (203 mm) to the parapet height required for Exposure C and the parapet height shall not be less than 12 inches (305 mm).

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▸ Contents — 2025 California Building Code (Title 24, Part 2)
2025 California Building Code (Title 24, Part 2)
  1. Chapter 1 — ADMINISTRATION
  2. Chapter 2 — DEFINITIONS
  3. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  4. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
  5. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  6. Chapter 6 — TYPES OF CONSTRUCTION
  7. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  8. Chapter 7A — MATERIALS AND CONSTRUCTION METHODS FOR EXTERIOR W…
  9. Chapter 8 — INTERIOR FINISHES
  10. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  11. Chapter 10 — MEANS OF EGRESS
  12. Chapter 11 — RESERVED
  13. Chapter 11A — HOUSING ACCESSIBILITY
  14. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  15. Chapter 12 — INTERIOR ENVIRONMENT
  16. Chapter 13 — ENERGY EFFICIENCY
  17. Chapter 14 — EXTERIOR WALLS
  18. ▸ Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
    Overview
    1. Section 1501 — GENERAL
    2. Section 1502 — ROOF DRAINAGE
    3. Section 1503 — WEATHER PROTECTION
    4. Section 1504 — PERFORMANCE REQUIREMENTS
    5. Section 1505 — FIRE CLASSIFICATION
    6. Section 1506 — MATERIALS
    7. Section 1507 — REQUIREMENTS FOR ROOF COVERINGS
    8. Section 1508 — ROOF INSULATION
    9. Section 1509 — ROOF COATINGS
    10. Section 1510 — RADIANT BARRIERS INSTALLED ABOVE DECK
    11. Section 1511 — ROOFTOP STRUCTURES
    12. Section 1512 — REROOFING
    13. Section 1513 — [DSA-SS & DSA-SS/CC, OSHPD 1, 1R, 2, 4 & 5] SEI…
  19. Chapter 16 — STRUCTURAL DESIGN
  20. Chapter 16A — STRUCTURAL DESIGN
  21. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  22. Chapter 17A — SPECIAL INSPECTIONS AND TESTS
  23. Chapter 18 — SOILS AND FOUNDATIONS
  24. Chapter 18A — SOILS AND FOUNDATIONS
  25. Chapter 19 — CONCRETE
  26. Chapter 19A — CONCRETE
  27. Chapter 20 — ALUMINUM
  28. Chapter 21 — MASONRY
  29. Chapter 21A — MASONRY
  30. Chapter 22 — STEEL
  31. Chapter 22A — STEEL
  32. Chapter 23 — WOOD
  33. Chapter 24 — GLASS AND GLAZING
  34. Chapter 25 — GYPSUM PANEL PRODUCTS AND PLASTER
  35. Chapter 26 — PLASTIC
  36. Chapter 27 — ELECTRICAL
  37. Chapter 28 — MECHANICAL SYSTEMS
  38. Chapter 29 — PLUMBING SYSTEMS
  39. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  40. Chapter 31 — SPECIAL CONSTRUCTION
  41. Chapter 31A — SYSTEMS FOR WINDOW CLEANING OR EXTERIOR BUILDING…
  42. Chapter 31B — PUBLIC POOLS
  43. Chapter 31C — RADIATION
  44. Chapter 31D — FOOD ESTABLISHMENTS
  45. Chapter 31F — MARINE OIL TERMINALS
  46. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  47. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  48. Chapter 34 — RESERVED
  49. Chapter 35 — REFERENCED STANDARDS
  50. Appendix A — EMPLOYEE QUALIFICATIONS
  51. Appendix B — BOARD OF APPEALS
  52. Appendix C — GROUP U—AGRICULTURAL BUILDINGS
  53. Appendix D — FIRE DISTRICTS
  54. Appendix E — RESERVED
  55. Appendix F — RODENTPROOFING
  56. Appendix G — FLOOD-RESISTANT CONSTRUCTION
  57. Appendix H — SIGNS
  58. Appendix I — PATIO COVERS
  59. Appendix J — GRADING
  60. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES PROTECTED B…
  61. Appendix L — EARTHQUAKE RECORDING INSTRUMENTATION
  62. Appendix M — TSUNAMI-GENERATED FLOOD HAZARDS
  63. Appendix N — REPLICABLE BUILDINGS
  64. Appendix O — PERFORMANCE-BASED APPLICATION
  65. Appendix P — SLEEPING LOFTS
  66. Appendix Q — EMERGENCY HOUSING

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