DALTON, Ohio-based Stairbuilders and Manufacturers Association (SMA), a collective of stair industry professionals specializing in residential and commercial construction, urges homebuilders to study and understand significant deficiencies regarding guard connections at engineered and conventional floor systems. The edge of floor structures, particularly those of engineered joist and truss components, were rotating when the top of the guard was loaded in the 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. The following new requirements are part of the 2024 International Residential Code (IRC), but we strongly encourage and support early adoption today!
New Requirements in the 2024 IRC
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 Sections 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 minimum net width of 3 inches (76mm) and a minimum net depth of 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 a minimum 6×10 sawn timber or a minimum 5-1/8 inch x 9-1/4 inch (130 mm x 235 mm) structural glued laminated timber 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 a minimum of 16 inches (406 mm) from the edge. Blocking shall have end connections with a minimum of six (6) – 16d common nails. Floor sheathing shall be continuous for a minimum of 24 inches (610 mm) from the edge and shall be fastened to each roll brace with a minimum of twelve (12) – 10d common nails and shall be fastened to the edge member with a minimum of twelve (12) – 10d common nails within 12 inches (305 mm) of the roll brace.
Early adoption of these significant changes in the IRC will eliminate the hidden potential danger of floor systems incapable of resisting the required live loads applied to the top of guards. We strongly encourage a deeper understanding of how these requirements will improve building safety, construction, and life cycle costs. The SMA, its stairbuilder, and supplier members want to avoid further delay and costly consequences.
The SMA was established in 1988 as the Stairway Manufacturers’ Association to ensure the growth and prosperity of the stair-making industry and craft. The main focus of the SMA is to reasonably establish empirical changes in stair, handrail, and guard codes and set an example for valid code reform.
