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Chapter 21 — MASONRY

Section 2107A

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.

ALLOWABLE STRESS DESIGN

2107 A .1 General. The design of masonry structures using allowable stress design shall comply with Section 2106 A and the requirements of Chapters 1 through 8 of TMS 402 except as modified by Sections 2107 A .2 through 2107A.6.

2107 A .2 TMS 402, Section 6.1.6.1.1, lap splices. As an alternative to Section 6.1.6.1.1, it shall be permitted to design lap splices in accordance with Section 2107 A .2.1.

2107 A .2.1 Lap splices. The minimum length of lap splices for reinforcing bars in tension or compression, ld, shall be:

ld = 0.002 db fs (Equation 21 A -1)

For SI: ld = 0.29 db fs but not less than 12 inches (305 mm). The length of the lapped splice shall be not less than 40 bar diameters.

where: db = Diameter of reinforcement, inches (mm). fs = Computed stress in reinforcement due to design

loads, psi (MPa).

In regions of moment where the design tensile stresses in the reinforcement are greater than 80 percent of the allowable steel tension stress, Fs, the lap length of splices shall be increased not less than 50 percent of the minimum required length, but need not be greater than 72 db . Other equivalent means of stress transfer to accomplish the same 50 percent increase shall be permitted. Where epoxy

TYPE OF MASONRY MAXIMUM RATIO
UNSUPPORTED
HEIGHT OR
LENGTH TO
THICKNESS2,3		 NOMINAL
MINIMUM
THICKNESS
(inches)
BEARING OR SHEAR WALLS:
1. Stone masonry
2. Reinforced grouted masonry
3. Reinforced hollow-unit masonry		 14
25
25		 16
6
6
NONBEARING WALLS:
4. Exterior reinforced walls
5. Interior partitions reinforced		 30
36		 6
4

1. For walls of varying thickness, use the least thickness when determining the height or length to thickness ratio. 2. In determining the height or length-to-thickness ratio of a cantilevered wall, the dimension to be used shall be twice the dimension of the end of the wall from the lateral support. 3. Cantilevered walls not part of a building and not carrying applied vertical loads need not meet these minimum requirements but their design must comply with stress and overturning requirements.

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

not be used in walls required to have a fire-resistance rating by other provisions of this code.

Exceptions:

  1. Glass-block assemblies having a fire protection rating of not less than 3 /4 hour shall be permitted as opening protectives in accordance with Section 716 in fire barriers, fire partitions and smoke barriers that have a required fire-resistance rating of 1 hour or less and do not enclose exit stairways and ramps or exit passageways.

  2. Glass-block assemblies as permitted in Section 404 A .6, Exception 2.

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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
    Overview
    1. Section 2102
    2. Section 2101
    3. Section 2103
    4. Section 2104
    5. Section 2105
    6. Section 2106
    7. Section 2107
    8. Section 2108
    9. Section 2109
    10. Section 2110
    11. Section 2111
    12. Section 2112
    13. Section 2113
    14. Section 2114
    15. Section 2115
    16. Section 2102A
    17. Section 2103A
    18. Section 2101A
    19. Section 2104A
    20. Section 2105A
    21. Section 2106A
    22. Section 2107A
    23. Section 2111A
    24. Section 2108A
    25. Section 2109A
    26. Section 2110A
    27. Section 2112A
    28. Section 2113A
    29. Section 2114A
  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
  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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