Section 2106 — SEISMIC DESIGN
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.
2106.1 Seismic design requirements for masonry. ¶
Masonry structures and components shall comply with the requirements in Chapter 7 of TMS 402 depending on the structure’s seismic design category.
2106.1.1 TMS 402, Sections 5.4.1.4. [OSHPD 1R, 2 & 5] Replace TMS 402, Section 5.4.1.4 Items (a), (b), (d) & (e) by the following: a. Vertical reinforcement shall be enclosed by lateral ties at least [3] / 8 inch ( 9.5 mm ) in diameter. b. Vertical spacing of lateral ties, over the full height of the column, shall not exceed 8 longitudinal bar diameters, 24 lateral tie bar diameters, 8 inches (203 mm), or one-half the least cross-sectional dimension of the member.
d. Lateral ties shall be embedded in grout. e. Lateral ties shall be located vertically not more than one-half lateral tie spacing above the top of the footing or slab in any story, and shall be spaced not more than one-half a lateral tie spacing nor 2 inches (51 mm) below the lowest horizontal reinforcement in beam, girder, slab, or drop panel above. The top tie shall be within 2 inches (51 mm) of the top of the column.
2106.1.2 TMS 402, Chapter 5. [OSHPD 1R, 2 & 5] Add TMS 402, Section 5.7 as follows:
5.7 – Lateral Support of Members
5.7.1 – Lateral support of masonry may be provided by cross walls, columns, pilasters, counterforts or buttresses where spanning horizontally, or by floors, beams, girts or roofs where spanning vertically. Where walls are supported laterally by vertical elements, the stiffness of each vertical element shall exceed that of the tributary area of the wall.
2106.1.3 TMS 402, Sections 7.4.4.1 and 7.4.5.1. [OSHPD 1R, 2 & 5] Replace TMS 402, Section 7.4.4.1 as follows and delete Section 7.4.5.1:
7.4.4.1 Minimum reinforcement requirements for masonry walls. The total area of reinforcement in reinforced masonry walls shall not be less than 0.003 times the sectional area of the wall. Neither the horizontal nor the vertical reinforcement shall be less than one third of the total. Horizontal and vertical reinforcement shall be spaced at not more than 24 inches (610 mm) center to center. Where other than running bond is used in reinforced hollow unit masonry, the open-end type of unit shall be used with vertical reinforcement spaced a maximum of 16 inches (406 mm) on center.
All cells shall be solidly filled with grout.
Exception: Reinforced hollow unit masonry used for freestanding site walls or interior nonbearing nonshear wall partitions shall have horizontal reinforcing spaced not more than 4 feet (1.2 m) on center, except for locations in Seismic Design Category F, and may be grouted only in cells containing vertical and horizontal reinforcement.
7.4.4.1.1 The minimum reinforcing shall be No. 4, except that No. 3 bars may be used for ties and stirrups. Vertical wall reinforce- ment shall have dowels of equal size and equally matched spacing in all footings. Reinforcement shall be continuous around wall corners and through intersections. Only reinforcement which is continuous in the wall shall be considered in computing the minimum area of reinforcement. Reinforcement with splices conforming to TMS 402 shall be considered as continuous reinforcement.
7.4.4.1.2 Horizontal reinforcing bars in bond beams shall be provided in the top of footings, at the top of wall openings, at roof and floor levels, and at the top of parapet walls. For walls 12 inches (nominal) (305 mm) or more in thickness, horizontal and vertical reinforcement shall be equally divided into two layers, except where designed as retaining walls. Where reinforcement is added above the minimum requirements, such additional reinforcement need not be so divided.
7.4.4.1.3 In bearing walls of every type of reinforced masonry, there shall be trim reinforcement of not less than one No. 5 bar or two No. 4 bars on all sides of, and adjacent to, every opening which exceeds 16 inches (406 mm) in either direction, and such bars shall extend not less than 48 diameters, but in no case less than 24 inches (610 mm) beyond the corners of the opening. The bars required by this paragraph shall be in addition to the minimum reinforcement required elsewhere.
7.4.4.1.4 When the reinforcement in bearing walls is designed, placed and anchored in position as for columns, the allowable stresses shall be as for columns.
7.4.4.1.5 Joint reinforcement shall not be used as principal reinforcement in masonry.
on Jul 18, 2025 11:14 AM (CDT) THEREUNDER.
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Ask AI about this code▸ Contents — 2025 California Building Code (Title 24, Part 2)
- Chapter 1 — ADMINISTRATION
- Chapter 2 — DEFINITIONS
- 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 METHODS FOR EXTERIOR W…
- Chapter 8 — INTERIOR FINISHES
- Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
- Chapter 10 — MEANS OF EGRESS
- Chapter 11 — RESERVED
- Chapter 11A — HOUSING ACCESSIBILITY
- Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
- Chapter 12 — INTERIOR ENVIRONMENT
- Chapter 13 — ENERGY EFFICIENCY
- 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 17A — SPECIAL INSPECTIONS AND TESTS
- Chapter 18 — SOILS AND FOUNDATIONS
- Chapter 18A — SOILS AND FOUNDATIONS
- Chapter 19 — CONCRETE
- Chapter 19A — CONCRETE
- Chapter 20 — ALUMINUM
-
▸ Chapter 21 — MASONRY
Overview- Section 2101 — GENERAL
- Section 2102 — NOTATIONS
- Section 2103 — MASONRY CONSTRUCTION MATERIALS
- Section 2104 — CONSTRUCTION
- Section 2105 — QUALITY ASSURANCE
- Section 2106 — SEISMIC DESIGN
- Section 2107 — ALLOWABLE STRESS DESIGN
- Section 2108 — STRENGTH DESIGN OF MASONRY
- Section 2109 — EMPIRICAL DESIGN OF ADOBE MASONRY
- Section 2110 — GLASS UNIT MASONRY
- Section 2111 — MASONRY FIREPLACES
- Section 2112 — MASONRY HEATERS
- Section 2113 — MASONRY CHIMNEYS
- Section 2114 — DRY-STACK MASONRY
- Section 2115 — ADDITIONAL REQUIREMENTS FOR COMMUNITY COLLEGES …
- Chapter 21A — MASONRY
- Chapter 22 — STEEL
- Chapter 22A — STEEL
- Chapter 23 — WOOD
- Chapter 24 — GLASS AND GLAZING
- Chapter 25 — GYPSUM PANEL PRODUCTS AND PLASTER
- Chapter 26 — PLASTIC
- Chapter 27 — ELECTRICAL
- Chapter 28 — MECHANICAL SYSTEMS
- Chapter 29 — PLUMBING SYSTEMS
- Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
- Chapter 31 — SPECIAL CONSTRUCTION
- Chapter 31A — SYSTEMS FOR WINDOW CLEANING OR EXTERIOR BUILDING…
- 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 34 — RESERVED
- Chapter 35 — REFERENCED STANDARDS
- Appendix A — EMPLOYEE QUALIFICATIONS
- Appendix B — BOARD OF APPEALS
- Appendix C — GROUP U—AGRICULTURAL BUILDINGS
- Appendix D — FIRE DISTRICTS
- Appendix E — RESERVED
- Appendix F — RODENTPROOFING
- Appendix G — FLOOD-RESISTANT CONSTRUCTION
- Appendix H — SIGNS
- Appendix I — PATIO COVERS
- Appendix J — GRADING
- Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES PROTECTED B…
- Appendix L — EARTHQUAKE RECORDING INSTRUMENTATION
- Appendix M — TSUNAMI-GENERATED FLOOD HAZARDS
- Appendix N — REPLICABLE BUILDINGS
- Appendix O — PERFORMANCE-BASED APPLICATION
- Appendix P — SLEEPING LOFTS
- Appendix Q — EMERGENCY HOUSING