Guard Connections at Engineered and Conventional Floor Systems

SMA members recognized a serious deficit in the building code.  The edge of floor structures particularly those of engineered joist and truss components were rotating when the top of the guard was loaded in final inspection.  A sound floor structure that could support the guard system when loaded was not provided even though the floor system was code compliant.

In the fall of 2021, the SMA formed an industry wide task group that included engineers, truss and I-joist manufacturers, builders, hardware manufacturers, railing fabricators, and stairbuilders.  A year later they had successfully changed the International Residential Code (IRC). Their change is now part of the 2024 IRC (full text below) but, it will not be effective until adopted by local jurisdictions.  Most communities have not yet adopted the 2021 version of the IRC.  Therefore, unless we act now, this problem will not be resolved for 5 or more years.

Why Wait? 

The SMA has developed resources to aid you in promoting adoption of these important structural changes to floor framing now.  Literature and presentations meant to educate local builders, design and building safety professionals, will be available soon.  Together the building community can emphasize to local building enforcement jurisdictions the need for early adoption to eliminate this structural deficit of the code. You can learn more by contacting your local SMA member.

Approved NEW Code for 2024 International Residential Code

IRC: R502.11, R502.11.1, 502.11.2, 502.11.3

Proponents: David Cooper, representing Stairbuilders and Manufacturers Association (; Erik Farrington, representing myself (; Renda Barr, representing Stairbuilders and Manufacturers Association (; Robert Aulicky, representing Stairbuilders & Manufacturers Association (; Marvin Strzyzewski, representing Truss Engineering Company (; Thomas Zuzik Jr, representing NOMMA (; Daniel Obrien, representing Universal Building
Systems, Inc. ( requests As Modified by Public Comment

2024 International Residential Code

R502.11 Floor framing supporting guards. The framing at the open edge of a floor supporting a required guard assembly shall be constructed in accordance with Section R502.11.1 or R502.11.2 for guard assemblies not exceeding 44 inches (1118mm) in height, or shall be designed in accordance with accepted engineering practice to support the guard assembly. Where trusses and I-joists are used as edge framing members supporting guards, the effects of the guard loads shall be specifically considered in the design of the edge member.

R502.11.1 Conventional edge framing. Where a roll brace is aligned with each guard post, the framing at the edge of the floor shall consist of a solid or built-up member of lumber, structural glued-laminated timber or structural composite lumber having a net width of not less than 3 inches (76mm) and a net depth of not less than 9-1/4 inches (235 mm), and shall be braced to resist rotation by roll bracing as described in Section R502.11.3 


R502.11.2 Timber edge framing. Where a roll brace is not aligned with each guard post, the framing at the edge of the floor shall consist of sawn timber not less than 6 inches by 10 inches or structural glued-laminated timber not less than 5-1/8 inches by 9-1/4 inches (130 mm x 235 mm)  and shall be braced to resist rotation by roll bracing as described in Section R502.11.3 at intervals of 48 inches (1219 mm) or less.

R502.11.3 Roll bracing. Each roll brace shall be a joist or blocking matching the depth of the edge member and extending perpendicular to the edge member not less than 16 inches (406 mm) from the edge. Blocking shall have end connections with not fewer than six 16d common nails. Floor sheathing shall be continuous for not less than 24 inches (610 mm) from the edge and shall be fastened to each roll brace with not fewer than 12 (twelve) 10d common nails and shall be fastened to the edge member with a minimum of 12 (twelve) 10d common nails within 12 inches (305 mm) of the roll brace.


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