Roof Bracing Requirements

The ceiling joists restrain the exterior walls from being thrust outwards as gravity loads such as snow push down on the roof.

Roof bracing requirements.

If your local building authority has a rafter spacing code you may not space rafters wider than required by code. The lower roof plan area no soffit 7 040 6 2 8 1 3 1 6 2 3 1 68 7 m. Truss bracing requirements are found in section r802 10 3. Roof braces can consist of either.

One roof brace is required per 50 m with a minimum of two per ridge line. Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. This is an area where the code requirements could be improved. Collar ties are required in the upper third of the roof system to provide restraint against the roof being pulled upward and outward from wind.

The bracing described in this brochure covers both framed roofs and fully trussed roofs. Truss web bracing is critical to the stability of the roof system yet very few residential projects have engineering observation of completed roof systems. This section requires trusses to be braced to prevent rotation and to provide lateral stability. Unless the truss spans 60 feet or more special inspection of the truss web bracing installation is not required.

Rafter spacing rafters must be strong enough to hold the roof sheathing and the shingles. Lower roof solution minimum of two braces are required for the lower storey roof but also a minimum of two per ridge line see figure 1. I roof plane brace or. Dormers porches do not require bracing.