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Chapter 16 — REFERENCED STANDARDS

Section A109

California Existing Building Code (Title 24, Part 10) · 2022 edition · updated 2026-09-10 · California

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

ANALYSIS AND DESIGN PROCEDURE

[BS] A109.1 General. The elements of buildings hereby required to be analyzed are specified in Table A102.1.

[BS] A109.2 Selection of procedure. Buildings with rigid diaphragms shall be analyzed by the general procedure of Section A110. Buildings with flexible diaphragms shall be analyzed by the general procedure or, where applicable, are permitted to be analyzed by the special procedure of Section A111.

vmL

= ----------------------------------1.5

fsp + P ------ D An

[BS] A108.3 Masonry compression. Where any increase in wall dead plus live load compression stress occurs, the maximum compression stress in unreinforced masonry, QG/An, shall not exceed 300 pounds per square inch (2070 kPa).

Copyright © 2022 by, or licensed to, International Code Council, Inc. (ALL RIGHTS RESERVED); licensed to California Building Standards Commission pursuant to License Agreement. No further reproductions is authorized. 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.

APPENDIX A—GUIDELINES FOR THE SEISMIC RETROFIT OF EXISTING BUILDINGS

[BS] TABLE A108.1(2) STRENGTH VALUES OF NEW MATERIALS USED IN CONJUNCTION WITH EXISTING CONSTRUCTION

NEW MATERIALS OR CONFIGURATION OF MATERIALS STRENGTH VALUES
Horizontal diaphragms Plywood sheathing applied directly over existing straight
sheathing with ends of plywood sheets bearing on joists or
rafters and edges of plywood located on center of individual
sheathing boards.		 675 lbs. per ft.
Crosswalls Plywood sheathing applied directly over wood studs; no
value should be given to plywood applied over existing plas-
ter or wood sheathing.		 1.2 times the value specified in the current building
code.
Crosswalls Drywall or plaster applied directly over wood studs. The value specified in the current building code.
Crosswalls Drywall or plaster applied to sheathing over existing wood
studs.		 50 percent of the value specified in the current
building code.
Tension anchorsf Anchors extending entirely through unreinforced masonry
wall secured with bearing plates on far side of a wall 30
square inches of area.b, c		 5,400 lbs. per anchor for three-wythe minimum
walls.
2,700 lbs. for two-wythe walls.
Shear boltse, f Anchors embedded not less than 8 inches into unreinforced
masonry walls; anchors should be centered in 21/2-inch-
diameter holes with dry-pack or nonshrink grout around the
circumference of the anchor.		 The value for plain masonry specified for solid
masonry TMS 402; and no value larger than those
given for3/4-inch bolts should be used.
Combined tension and
shear anchorsf		 Through-anchors—anchors meeting the requirements for
shear and for tension anchors.b, c		 Tension—same as for tension anchors.
Shear—same as for shear anchors.
Combined tension and
shear anchorsf		 Embedded anchors—anchors extending to the exterior face
of the wall with a 21/2-inch round plate under the head and
drilled at an angle of 221/2 degrees to the horizontal; installed
as specified for shear anchors.a, b, c		 Tension—3,600 lbs. per anchor.
Shear—same as for shear anchors.
Infilled walls Reinforced masonry infilled openings in existing unrein-
forced masonry walls; provide keys or dowels to match rein-
forcing.		 Same as values specified for unreinforced masonry
walls.
Reinforced masonryd Masonry piers and walls reinforced per the current building
code.		 The value specified in the current building code for
strength design.
Reinforced concreted Concrete footings, walls and piers reinforced as specified in
the current building code.		 The value specified in the current building code for
strength design.

For SI: 1 inch = 25.4 mm, 1 square inch = 645.16 mm 2, 1 pound = 4.4 N, 1 degree = 0.017 rad, 1 pound per foot = 14.43 N/m, 1 foot = 304.8 mm. a. Embedded anchors to be tested as specified in Section A107.4. b. Anchors shall be 1 /2 inch minimum in diameter. c. Drilling for anchors shall be done with an electric rotary drill; impact tools should not be used for drilling holes or tightening anchors and shear bolt nuts. d. Load factors or capacity reduction factors shall not be used. e. Other bolt sizes, values and installation methods may be used, provided that a testing program is conducted in accordance with Section A107.5.3. The strength

value shall be determined by multiplying the calculated allowable value, determined in accordance with Section A107.5.3, by 3.0, and the usable value shall be limited to not greater than 1.5 times the value given in the table. Bolt spacing shall not exceed 6 feet on center and shall be not less than 12 inches on center. f. An alternative adhesive anchor bolt system is permitted to be used providing: its properties and installation conform to an ICC Evaluation Service Report; and

the report states that the system’s use is in unreinforced masonry as an acceptable alternative to Sections A107.4 and A113.1 or TMS 402, Section 2.1.4. The report’s allowable values shall be multiplied by a factor of three to obtain strength values and the strength reduction factor, Φ, shall be taken equal to 1.0.

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▸Contents — California Existing Building Code (Title 24, Part 10)
California Existing Building Code (Title 24, Part 10)
  1. Chapter 2 — DEFINITIONS
  2. Appendix A — GUIDELINES FOR
  3. Appendix B — SUPPLEMENTARY
  4. Appendix C — GUIDELINES FOR THE WIND
  5. Appendix D — BOARD OF
  6. Chapter 1 — SCOPE AND ADMINISTRATION
  7. Chapter 3 — PROVISIONS FOR ALL COMPLIANCE METHODS
  8. Chapter 4 — REPAIRS
  9. Chapter 5 — PRESCRIPTIVE COMPLIANCE METHOD
  10. Chapter 6 — CLASSIFICATION OF WORK
  11. Chapter 7 — ALTERATIONS—LEVEL 1
  12. Chapter 8 — ALTERATIONS—LEVEL 2
  13. Chapter 9 — ALTERATIONS—LEVEL 3
  14. Chapter 10 — CHANGE OF OCCUPANCY
  15. Chapter 11 — ADDITIONS
  16. Chapter 12 — HISTORIC BUILDINGS
  17. Chapter 13 — PERFORMANCE COMPLIANCE METHODS
  18. Chapter 14 — RELOCATED OR MOVED BUILDINGS
  19. Chapter 15 — CONSTRUCTION SAFEGUARDS
  20. ▸Chapter 16 — REFERENCED STANDARDS
    Overview
    1. Section A100
    2. Section A101
    3. Section A102
    4. Section A103
    5. Section A104
    6. Section A105
    7. Section A106
    8. Section A107
    9. Section A108
    10. Section A109
    11. Section A110
    12. Section A111
    13. Section A112
    14. Section A113
    15. Section A114
    16. Section A201
    17. Section A202
    18. Section A203
    19. Section A204
    20. Section A205
    21. Section A206
    22. Section A207
    23. Section A301
    24. Section A302
    25. Section A303
    26. Section A304
    27. Section A401
    28. Section A403
    29. Section A402
    30. Section A404
    31. Section A405
    32. Section A406
    33. Section A407
    34. Section A501
    35. Section B101
    36. Section B102
    37. Section B103
    38. Section B104
    39. Section C101
    40. Section C102
    41. Section C103
    42. Section C104
    43. Section C201
    44. Section C202
    45. Section C301
    46. Section D101

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