Skip to content

Appendix A — GUIDELINES FOR THE SEISMIC RETROFIT OF EXISTING BUILDINGS

Section A405 — MATERIALS OF CONSTRUCTION

2025 California Existing Building Code (Title 24, Part 10) · 2025 edition · updated 2026-07-27 · California

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

[BS] A405.1 New materials. New materials shall meet the requirements of the California Building Code, except where allowed by this chapter.

[BS] A405.2 Allowable foundation and lateral pressures. The use of default values from the building code for continuous and isolated concrete spread footings shall be permitted. For soil that supports embedded vertical elements, Section A403.4.1 shall apply.

[BS] A405.3 Existing materials. The physical condition, strengths and stiffnesses of existing building materials shall be taken into account in any analysis required by this chapter. The verification of existing materials conditions and their conformance to these requirements shall be made by physical observation, material testing or record drawings as determined by the registered design professional subject to the approval of the code official.

[BS] A405.3.1 Wood-structural-panel shear walls.

[BS] A405.3.1.1 Existing nails. Where the required calculations rely on design values for common nails or surfaced dry lumber, their use in construction shall be verified by exposure.

[BS] A405.3.1.2 Existing plywood. Where verification of the existing plywood is by use of record drawings alone, plywood shall be assumed to be of three plies.

[BS] A405.3.2 Existing wood framing. Wood framing is permitted to use the design stresses specified in the building code under which the building was constructed or other stress criteria approved by the code official.

[BS] A405.3.3 Existing structural steel. All existing structural steel shall be permitted to be assumed to comply with ASTM A36. Existing pipe or tube columns shall be assumed to be of minimum wall thickness unless verified by testing or exposure.

[BS] A405.3.4 Existing concrete. All existing concrete footings shall be permitted to be assumed to be plain concrete with a compressive strength of 2,000 pounds per square inch (13.8 MPa). Existing concrete compressive strength taken greater than 2,000 pounds per square inch (13.8 MPa) shall be verified by testing, record drawings or department records.

[BS] A405.3.5 Existing sill plate anchorage. The analysis of existing cast-in-place anchors shall be permitted to assume proper anchor embedment for purposes of evaluating shear resistance to lateral loads.

Get a plain-English answer with a citation back to this text.

Ask AI about this code
▸ Contents — 2025 California Existing Building Code (Title 24, Part 10)
2025 California Existing Building Code (Title 24, Part 10)
  1. 104.11 for consideration of alternative means of compliance.
  2. Chapter 1 — ADMINISTRATION
  3. Chapter 2 — DEFINITIONS
  4. Chapter 3 — PROVISIONS FOR ALL COMPLIANCE METHODS
  5. Chapter 3A — PROVISIONS FOR ALL COMPLIANCE METHODS
  6. Chapter 4 — REPAIRS
  7. Chapter 4A — REPAIRS
  8. Chapter 5 — PRESCRIPTIVE COMPLIANCE METHOD
  9. Chapter 5A — 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
  21. ▸ Appendix A — GUIDELINES FOR THE SEISMIC RETROFIT OF EXISTING B…
    Overview
    1. Section A100 — APPLICATION
    2. Section A101 — PURPOSE
    3. Section A102 — SCOPE
    4. Section A103 — DEFINITIONS
    5. Section A104 — SYMBOLS AND NOTATIONS
    6. Section A105 — GENERAL REQUIREMENTS
    7. Section A106 — MATERIALS REQUIREMENTS
    8. Section A107 — QUALITY CONTROL
    9. Section A108 — DESIGN STRENGTHS
    10. Section A109 — ANALYSIS AND DESIGN PROCEDURE
    11. Section A110 — GENERAL PROCEDURE
    12. Section A111 — SPECIAL PROCEDURE
    13. Section A112 — ANALYSIS AND DESIGN
    14. Section A113 — DETAILED BUILDING SYSTEM DESIGN REQUIREMENTS
    15. Section A114 — WALLS OF UNBURNED CLAY, ADOBE OR STONE MASONRY
    16. Section A201 — PURPOSE
    17. Section A202 — SCOPE
    18. Section A203 — DEFINITIONS
    19. Section A204 — SYMBOLS AND NOTATIONS
    20. Section A205 — GENERAL REQUIREMENTS
    21. Section A206 — ANALYSIS AND DESIGN
    22. Section A207 — MATERIALS OF CONSTRUCTION
    23. Section A301 — GENERAL
    24. Section A302 — DEFINITIONS
    25. Section A303 — STRUCTURAL WEAKNESSES
    26. Section A304 — STRENGTHENING REQUIREMENTS
    27. Section A401 — GENERAL
    28. Section A402 — DEFINITIONS
    29. Section A403 — ANALYSIS AND DESIGN
    30. Section A404 — PRESCRIPTIVE MEASURES FOR WEAK STORY
    31. Section A405 — MATERIALS OF CONSTRUCTION
    32. Section A406 — CONSTRUCTION DOCUMENTS
    33. Section A407 — QUALITY CONTROL
    34. Section A501 — REFERENCED STANDARDS
  22. Appendix B — SUPPLEMENTARY ACCESSIBILITY REQUIREMENTS FOR EXIS…
  23. Appendix C — GUIDELINES FOR THE WIND RETROFIT OF EXISTING BUIL…
  24. Appendix D — BOARD OF APPEALS
  25. Appendix E — TEMPORARY EMERGENCY USES
  26. Appendix A — GUIDELINES ON FIRE RATINGS OF ARCHAIC MATERIALS A…

GoCodebook provides public access, search, citation, multilingual explanation, and practical interpretation of legally adopted building regulations. It is not a substitute for the official ICC or California code publications.