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Chapter 21A — MASONRY

Section 2104A — CONSTRUCTION

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.

2104 A .1 Masonry construction. Masonry construction shall comply with the requirements of Sections 2104 A .1.1 through 2104 A .1.3 and with the requirements of either TMS 602 or TMS 604.

2104 A .1.1 Support on wood. Masonry shall not be supported on wood girders or other forms of wood construction except as permitted in Section 2304 A .13.

2104 A .1.2 Molded cornices. Unless structural support and anchorage are provided to resist the overturning moment, the center of gravity of projecting masonry or molded cornices shall lie within the middle one-third of the supporting wall. Terra cotta and metal cornices shall be provided with a structural frame of approved noncombustible material anchored in an approved manner.

2104A.1.3 Reinforced grouted masonry.

2104A.1.3.1 [DSA-SS] TMS 602, Article 3.2 F Cleanouts. Replace TMS 602, Article 3.2 F with the following:

3.2 F. Cleanouts - Provide cleanouts in the bottom course of masonry for each grout pour when the grout pour height exceeds the height limits given in Section 2104A.1.3.5 Item 3. 1. Cleanout openings in hollow unit masonry shall be provided in every cell at the bottom of each pour of grout. Alterna- tively, if the course at the bottom of the pour is constructed entirely of inverted double open-end bond beam units, cleanout openings need only be provided for access to every reinforced cell at the bottom of each pour of grout. 2. Cleanouts in multi-wythe masonry shall be provided for each pour by leaving out every other unit in the bottom wythe of the section being poured or by cleanout openings in the foundation. 3. The foundation or other horizontal construction joints at the cleanouts shall be cleaned of all loose material and mortar droppings before each pour. The cleanouts shall be sealed after inspection and before grouting.

2104A.1.3.2 TMS 602, Article 3.3 B Placing mortar and units. Modify TMS 602, Article 3.3 B.2.c as follows: c. Remove masonry protrusions extending greater than [1] / 4 inch ( 6.4 mm) into cells or cavities to be grouted.

2104A.1.3.3 TMS 602, Article 3.4 B Reinforcement. Modify TMS 602, Article 3.4 B.1 through Article 3.4 B.3 as follows:

  1. Support reinforcement to prevent displacement caused by construction loads or by placement of grout or mortar. Reinforcement and embedded items shall be clean, properly positioned and securely anchored against moving prior to grouting.
  2. Completely embed reinforcing bars and embedded items in grout in accordance with Article 3.5.
  3. Maintain clear distance between reinforcing bars and the interior of masonry unit or formed surface of at least [1] / 2 inch (12.7 mm), and a minimum of one bar diameter, except where cross webs of hollow units are used as supports for horizontal reinforcement.

nst moving prior to_ grouting. 2. Completely embed reinforcing bars and embedded items in grout in accordance with Article 3.5. 3. Maintain clear distance between reinforcing bars and the interior of masonry unit or formed surface of at least [1] / 2 inch (12.7 mm), and a minimum of one bar diameter, except where cross webs of hollow units are used as supports for horizontal reinforcement.

2104A.1.3.4 TMS 602, Article 3.4 E Anchor bolts. Replace TMS 602, Article 3.4 E.3 and add Articles 3.4 E.5 and 3.4 E.6 as follows: 3. Anchor bolts in the wythe or face shells of hollow masonry units shall be positioned to maintain a minimum of [1] / 2 inch (12.7 mm) of grout between the bolt circumference and the wythe or the face shell. For the portion of the bolt that is within the grouted cell, maintain a clear distance between the bolt and the face of masonry unit and between the head of the bolt and

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

MASONRY

the formed surface of grout of at least [1] / 4 inch (6.4 mm) when using fine grout and at least [1] / 2 inch (12.7 mm) when using coarse grout. Bolts shall be solidly embedded in grout. 5. Bent bar anchor bolts shall not be allowed. The maximum size anchor shall be [1] / 2 -inch (12.7 mm) diameter for 6-inch (152 mm) nominal masonry, [3] / 4 -inch (19.1 mm) diameter for 8-inch (203 mm) nominal masonry, [7] / 8 -inch (22 mm) diameter for 10- inch (254 mm) nominal masonry, and 1-inch (25.4 mm) diameter for 12-inch (305 mm) nominal masonry. 6. Bolts shall be accurately set with templates or by approved equivalent means and held in place to prevent dislocation during grouting.

2104A.1.3.5 [DSA-SS] TMS 602, Article 3.5 C Grout pour height. Replace TMS 602, Article 3.5 C and Table 7 as follows: 1. Do not exceed the grout pour height given in Table 7. Grout pours not terminated at the top of constructed masonry shall comply with TMS 602, Articles 3.5 C.3.a through 3.5 C.3.c. 2. The top of the grout pour shall be in the top course of the constructed masonry. Grout pours not terminated within the top course of the constructed masonry shall comply with TMS 602, Articles 3.5 C.3.a through 3.5 C.3.c. 3. Grout pours in excess of 4 feet (1219 mm) or 5 feet 4 inches (1651 mm) for 10-inch (254 mm) nominal or wider for hollow unit masonry shall be subject to approval of the enforcement agency and the following: a. Grouting shall be done in a continuous pour in lifts not exceeding the requirements of TMS 602, Article 3.5 D. b. The grouting of any section of wall shall be completed in one day with no interruptions greater than one hour. c. Cleanout openings shall be provided at the bottom of each pour of grout.

masonry shall be subject to approval of the enforcement agency and the following: a. Grouting shall be done in a continuous pour in lifts not exceeding the requirements of TMS 602, Article 3.5 D. b. The grouting of any section of wall shall be completed in one day with no interruptions greater than one hour. c. Cleanout openings shall be provided at the bottom of each pour of grout.

TABLE 7—GROUT SPACE REQUIREMENTS

GROUT TYPE1 MAXIMUM GROUT POUR
HEIGHT, FT (M)		 MINIMUM CLEAR WIDTH OF
GROUT SPACE,2,3 IN. (MM)		 MINIMUM CLEAR GROUT SPACE DIMENSIONS
**FOR GROUTING CELLS OF HOLLOW UNITS,3 **
IN. × IN. (MM × MM)
Coarse 1 (0.3) 21/2 (63.5) 2 × 3(50.8× 76.2)
Coarse 44 (1.22) 21/2 (63.5) 21/2 × 3 (63.5 × 76.2)
Coarse 12.675 (3.86) 31/2 (88.9) 3 × 35 (76.2 × 76.2)
1. Coarse grout is defined in ASTM C476.
2. For grouting between masonry wythes.
3. Minimum clear width of grout space and minimum clear grout space dimension are the net dimension of the space determined by subtracting masonry protrusions and the
diameters of horizontal reinforcement from the as-built cross section of the grout space.
4. Maximum pour height can be increased to 5.33 feet for 10-inch nominal or wider hollow unit masonry.
5. Maximum pour height can be increased to 16 feet for hollow unit masonry walls with a nominal thickness of 12 inches or more and minimum clear grout space dimensions of 3 in.
x 4 in. (76.2 mm x 102 mm).

2104A.1.3.6 [DSA-SS] TMS 602, Article 3.5 D Grout lift height. Modify TMS 602, Article 3.5 D as follows: 3. Grout lift height shall not exceed 4 feet (1219 mm). Exception: The 4 feet (1219 mm) maximum lift height may be increased to 5 feet 4 inches (1.63 m) for 10-inch (254 mm) nominal and larger hollow unit masonry.

2104A.1.3.7 Reserved.

2104A.1.3.8 TMS 602, Article 3.5 F.1 Grout key. Replace TMS 602, Article 3.5 F.1 as follows: 1. Between grout pours or where grouting has been stopped more than an hour, a horizontal construction joint shall be formed by terminating grout a minimum of 1 [1] / 2 inches (38.1 mm) and a maximum of one-half the masonry unit height below a mortar joint, except at the top of the wall. Where bond beams occur, the grout pour shall be terminated a mini- mum of [1] / 2 inch (12.7 mm) below the mortar joint. Horizontal reinforcement shall be placed in bond beam units with a minimum grout cover of 1 inch (25.4 mm) above reinforcing steel for each grout pour.

2104A.1.3.9 TMS 602, Article 3.5 Grout placement. Add the following to TMS 602, Article 3.5:

3.5 I. Additional grouting requirements: 1. Place grout by pumping or an approved alternate method prior to initial set and loss of plasticity. 2. Place grout so that all spaces to be grouted do not contain voids. 3. Grout shall not be handled nor pumped utilizing aluminum equipment unless it can be demonstrated with the materials and equipment to be used that there will be no deleterious effect on the strength of the grout.

2104A.1.3.10 Reinforced grouted multi-wythe masonry.

2104A.1.3.10.1 General. Reinforced grouted multi-wythe masonry is that form of composite construction made with clay or shale brick or made with solid concrete building brick in which interior spaces of masonry are filled by pouring grout around reinforcement therein as the work progresses.

21A-6 2025 CALIFORNIA BUILDING CODE

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

MASONRY

2104A.1.3.10.2 TMS 402, Section 5.1.3.2 Composite action. Replace TMS 402, Section 5.1.3.2.1 by the following:

5.1.3.2.1 Multiwythe masonry designed for composite action shall have wythes connected by collar joints and wall ties.

2104A.1.3.10.3 TMS 602, Article 3.3 B.4 Placing mortar and units – Solid units. Add the following to TMS 602, Article 3.3 B.4: d. Toothing of masonry walls is prohibited. Racking is to be held to a minimum.

2104A.1.3.10.4 TMS 602, Article 3.4 C.2 Wall ties. Replace TMS 602, Article 3.4 C.2 as follows: 2. The two wythes shall be bonded together with wall ties. Ties shall not be less than No. 9 (W1.7) wire in the form of rect- angles 4 inches (102 mm) wide and 2 inches (50.8 mm) in length less than the overall wall thickness. Kinks, water drips or deformations shall not be permitted in the ties. One wythe of the wall shall be built up not more than 16 inches (406 mm) ahead of the other wythe. Ties shall be laid not to exceed 24 inches (610 mm) on center horizontally and 16 inches (406 mm) on center vertically for running bond, and not more than 24 inches (610 mm) on center horizontally and 12 inches (305 mm) on center vertically for other than running bond.

2104A.1.3.10.5 TMS 602, Article 3.5 B Confinement. Add the following to TMS 602, Article 3.5 B: 1. Construct vertical grout barriers or dams of solid masonry across the grout space the entire height of the wall to control horizontal grout flow. Space grout barriers not more than 30 feet (9.14 m) apart.

2104A.1.3.11 Reinforced hollow unit masonry.

2104A.1.3.11.1 TMS 602, Article 2.3 A & 2.3 B Masonry unit materials. Add the following to TMS 602, Articles 2.3 A and 2.3 B: 1. In reinforced hollow unit masonry, place horizontal reinforcement in bond beam units. The depth of the bond beam channel below the top of the unit shall be 1 [1] / 2 inches (38.1 mm) minimum and the width shall be 3 inches (76.2 mm) minimum.

2104A.1.3.11.2 TMS 602, Article 3.5 B Confinement. Add the following to TMS 602, Article 3.5 B: 2. All cells shall be solidly filled with grout in reinforced hollow unit masonry. Exception: Reinforced hollow unit masonry laid in running bond used for freestanding site walls or interior nonbear- ing non-shear wall partitions may be grouted only in cells containing vertical and horizontal reinforcement. 3. [DSA-SS] Vertical cells to be filled shall have vertical alignment sufficient to maintain a clear grout space dimension of not less than that given in Section 2104A.1.3.5, Table 7.

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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
  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
    Overview
    1. Section 2101A — GENERAL
    2. Section 2102A — NOTATIONS
    3. Section 2103A — MASONRY CONSTRUCTION MATERIALS
    4. Section 2104A — CONSTRUCTION
    5. Section 2105A — QUALITY ASSURANCE
    6. Section 2106A — SEISMIC DESIGN
    7. Section 2107A — ALLOWABLE STRESS DESIGN
    8. Section 2108A — STRENGTH DESIGN OF MASONRY
    9. Section 2109A — EMPIRICAL DESIGN OF ADOBE MASONRY
    10. Section 2110A — GLASS UNIT MASONRY
    11. Section 2111A — MASONRY FIREPLACES
    12. Section 2112A — MASONRY HEATERS
    13. Section 2113A — MASONRY CHIMNEYS
    14. Section 2114A — DRY-STACK 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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