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Chapter 24 — GLASS AND GLAZING

Section 2411 — [OSHPD 1, 1R, 2, 4 & 5]

California Building Code (Title 24, Part 2) · 2022 edition · updated 2026-09-12 · California

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

THERMAL BARRIERS IN ALUMINUM MULLION SYSTEMS

2411.1 General.

The requirements of this section address the use of thermal barriers composite in aluminum mullion sys- tems. The thermal barriers shall consist of either poured and debridged or mechanically locked pre-formed construction. The thermal barrier systems used shall be those tested and complying with AAMA TIR-A8. The thermal barrier manufac- turer, formulation number or insulating strut size/material and aluminum extrusions shall be consistent between testing, design and construction.

Exception: Single-story Type V skilled nursing or interme- diate care facilities utilizing wood-frame or light-steel- frame construction.

2411.1.1 Structural Design. Structural design of thermal barrier mullions shall satisfy the following requirements:

1. The allowable design stresses for thermal barrier materials composite with aluminum extrusions shall be determined by AAMA TIR-A8 testing for in-plane shear, tension and eccentric load at a minimum of ambient and high temperature using a factor of safety determined by AAMA TIR-A8 Section 6.7.

2. The shear modulus, Gc, of the thermal barrier in similar composite aluminum extrusions shall be determined by AAMA TIR-A8 testing for flexure in AAMA TIR-A8 Section 7.2 at a minimum of ambient and high temperature.

3. The aluminum extrusions used to determine allow- able stresses in the thermal barriers and the shear modulus, Gc, shall be from a specific aluminum extrusion manufacturer and the aluminum sections used in the project. The similarity of the composite

aluminum extrusions shall be subject to approval by the building official. 4. The effective moment of inertia of the in-plane com- posite thermal barrier-aluminum section used in flexural design, based upon the tested Gc, shall not exceed 85 percent of the moment of inertia of the combined unbridged aluminum portions of the com- posite section, unless substantiated and approved by the building official. 5. A high temperature of not less than 120°F shall be used for composite section flexure design for wind pressure where the historical high temperature exceeds 100°F. The minimum high temperature for in-plane shear, tension and eccentric load thermal barrier design shall be determined by AAMA TIR- A8 Section 6.5. 6. The lowest allowable stress value and shear modu- lus, Gc, from the ambient and high temperature test- ing shall be used for design. 7. Structural analysis and design for loads on pour and debridged thermal barriers with skip-debridging that has not been tested under AAMA TIR-A8 with skip-debridged test specimens for the specific actions or load direction shall be based upon the relative stiffness between the remaining aluminum bridge and the thermal barrier material and size. 8. Reactions on supporting thermal barrier mullions where the thermal barrier resists the concentrated load, the load shall not be assumed to be distributed over a length greater than 12 inches (305 mm) on the supporting mullion. 9. Mechanically locked, preformed thermal barriers shall be designed and used in pairs. 2411.1.2 Testing and Inspection. Testing and Inspection of thermal barrier mullions shall satisfy the following requirements:

1. Thermal barrier material properties shall be tested in accordance with AAMA TIR-A8 Section 6.1 by the manufacturer. All other testing shall done by an approved testing laboratory or agency. 2. Testing shall include AAMA TIR-A8 Section 7.2 for the flexural tests using the composite section under ambient and high temperature. Thermocouples shall be placed on the outside and interior surfaces and in the middle of the thermal barrier for high tempera- ture testing. Test cycles shall be in accordance with AAMA TIR-A8 Section 7.2.3. 3. Testing shall include AAMA TIR-A8 Section 7.3 for in-plane shear, tension and eccentric load using the composite section under ambient and high tempera- ture. 4. The flexural test for the composite section shall include a span length of 12 feet (3660 mm). The maximum P load in the test shall generate close to a L/175 deflection, where L is the span length, center to center of supports, but shall not exceed the allow- able design stresses for the aluminum composite

24-12 2022 CALIFORNIA BUILDING CODE

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.

section in meeting that deflection. Permanent deflec- tion shall not exceed the requirement in AAMA TIR- A8 Section 7.2.2.5. 5. A minimum of two different simple span lengths shall be used to determine Gc under the flexural test. The span lengths tested shall include a short span. 6. The shear modulus, Gc, of the thermal barrier shall be determined using the lowest average Iet from the flexural testing for each composite aluminum extru- sion, temperature and span length tested. 7. Each different composite aluminum extrusion in the project shall be tested to the requirements of AAMA TIR-A8. The magnitude of eccentricity of load on the thermal barrier shall be considered in selecting composite aluminum extrusions for testing. 8. The applicability of existing AAMA TIR-A8 testing of thermal barrier mullions that satisfy the require- ments of this section shall be permitted, in lieu of project-specific tests, when approved by the building official. 9. Periodic special inspection to ensure compliance with the AAMA TIR-A8 processing for the thermal isolator material shall be performed. Inspections shall include tests of thermal barrier material prop- erties per the manufacturer’s recommendation and AAMA TIR-A8 Section 6.1 and composite perfor- mance requirements per AAMA TIR-A8 Sections 7.2 and 7.3. 10. Periodic special inspection of pour and debridge thermal barrier shall include:

GLASS AND GLAZING

b. Verification that the mechanical lock cavity

distortion and locking distortion does not exist as set forth in AAMA TIR-A8 Sections 4.1.3.3 and 4.1.3.4. c. Verification of proper knurling of the alumi-

num and crimping of the insulating struts per AAMA TIR-A8 Section 4.2.2. d. Confirmation of proper manufacturing pro-

cess per the manufacturer’s recommenda- tions and AAMA TIR-A8 Section 4.5. e. Inspection of fabrication and handling prac-

tices in accordance with AAMA TIR-A8 Sec- tions 4.5 and 4.6.

a. Verification that the thermal barrier formula-

tion being used matches that in the design and construction documents. b. Verification that poured wet or dry shrinkage

as set forth in AAMA TIR-A8 Section 4.1.3.1 does not occur. c. Proper adhesion of poured thermal barrier

material per AAMA TIR-A8 Section 4.2.1. d. Confirmation of proper manufacturing pro-

cess per the manufacturer’s recommenda- tions and AAMA TIR-A8 Section 4.3. e. Inspection of fabrication and handling prac-

tices in accordance with AAMA TIR-A8 Sec- tions 4.3 and 4.4. f. Testing for thermal barrier material proper-

ties per the manufacturer’s recommendation and AAMA TIR-A8 Section 6.1. g. Periodic special inspection of the removal of

the temporary thermal bridge shall be provided to ensure that no thermal barrier material is removed in the process. 11. Periodic special inspection of mechanically locked, preformed thermal barriers shall include:

a. Verification that the insulating struts being

used match those in the design and construc- tion documents.

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.

24-14 2022 CALIFORNIA BUILDING CODE

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.

CALIFORNIA BUILDING CODE – MATRIX ADOPTION TABLE

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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. Appendix N — REPLICABLE
  6. Appendix O — PERFORMANCE-BASED
  7. Chapter 1 — SCOPE AND ADMINISTRATION
  8. Chapter 3 — OCCUPANCY CLASSIFICATION AND USE
  9. Chapter 4 — SPECIAL DETAILED REQUIREMENTS BASED ON OCCUPANCY A…
  10. Chapter 5 — GENERAL BUILDING HEIGHTS AND AREAS
  11. Chapter 6 — TYPES OF CONSTRUCTION
  12. Chapter 7 — FIRE AND SMOKE PROTECTION FEATURES
  13. Chapter 7A — MATERIALS AND CONSTRUCTION
  14. Chapter 8 — INTERIOR FINISHES
  15. Chapter 9 — FIRE PROTECTION AND LIFE SAFETY SYSTEMS
  16. Chapter 10 — MEANS OF EGRESS
  17. Chapter 11A — HOUSING ACCESSIBILITY
  18. Chapter 11B — ACCESSIBILITY TO PUBLIC BUILDINGS, PUBLIC ACCOMM…
  19. Chapter 12 — INTERIOR ENVIRONMENT
  20. Chapter 14 — EXTERIOR WALLS
  21. Chapter 15 — ROOF ASSEMBLIES AND ROOFTOP STRUCTURES
  22. Chapter 16 — STRUCTURAL DESIGN
  23. Chapter 16A — STRUCTURAL DESIGN
  24. Chapter 17 — SPECIAL INSPECTIONS AND TESTS
  25. Chapter 18 — SOILS AND FOUNDATIONS
  26. Chapter 19 — CONCRETE
  27. Chapter 20 — ALUMINUM
  28. Chapter 21 — MASONRY
  29. Chapter 22 — STEEL
  30. Chapter 23 — WOOD
  31. ▸Chapter 24 — GLASS AND GLAZING
    Overview
    1. Section 2401
    2. Section 2402
    3. Section 2403
    4. Section 2404
    5. Section 2405
    6. Section 2406
    7. Section 2407
    8. Section 2408
    9. Section 2409
    10. Section 2410
    11. Section 2411 — [OSHPD 1, 1R, 2, 4 & 5]
  32. Chapter 25 — GYPSUM BOARD, GYPSUM PANEL PRODUCTS AND PLASTER
  33. Chapter 26 — PLASTIC
  34. Chapter 27 — ELECTRICAL
  35. Chapter 28 — MECHANICAL SYSTEMS
  36. Chapter 30 — ELEVATORS AND CONVEYING SYSTEMS
  37. Chapter 31 — SPECIAL CONSTRUCTION
  38. Chapter 31B — PUBLIC POOLS
  39. Chapter 31C — RADIATION
  40. Chapter 31D — FOOD ESTABLISHMENTS
  41. Chapter 31F — MARINE OIL TERMINALS
  42. Chapter 32 — ENCROACHMENTS INTO THE PUBLIC RIGHT-OF-WAY
  43. Chapter 33 — SAFEGUARDS DURING CONSTRUCTION
  44. Chapter 35 — REFERENCED STANDARDS
  45. Appendix A — EMPLOYEE QUALIFICATIONS
  46. Appendix B — BOARD OF APPEALS
  47. Appendix C — GROUP U – AGRICULTURAL BUILDINGS
  48. Appendix D — FIRE DISTRICTS
  49. Appendix F — RODENTPROOFING
  50. Appendix H — SIGNS
  51. Appendix I — PATIO COVERS
  52. Appendix J — GRADING
  53. Appendix K — GROUP R-3 AND GROUP R-3.1 OCCUPANCIES
  54. Appendix P — EMERGENCY HOUSING

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