Roof Bracing Requirements

Truss bracing requirements are found in section r802 10 3.

Roof bracing requirements.

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. Truss web bracing is critical to the stability of the roof system yet very few residential projects have engineering observation of completed roof systems. If your local building authority has a rafter spacing code you may not space rafters wider than required by code. The bracing described in this brochure covers both framed roofs and fully trussed roofs.

Roof braces can consist of either. Dormers porches do not require bracing. This is an area where the code requirements could be improved. Roof planes less than 6m2 e g.

Unless the truss spans 60 feet or more special inspection of the truss web bracing installation is not required. One roof brace per 50m2 of roof area see rule 8 for minimum requirements one roof brace per 25m2 of roof area see rule 8 for minimum requirements 1. This section requires trusses to be braced to prevent rotation and to provide lateral stability. It allows the bracing requirement to be specified in the construction documents or on the individual truss design drawings.

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. The ceiling joists restrain the exterior walls from being thrust outwards as gravity loads such as snow push down on the roof. The lower roof plan area no soffit 7 040 6 2 8 1 3 1 6 2 3 1 68 7 m.