Roof Bracing Requirements

The bracing described in this brochure covers both framed roofs and fully trussed roofs.

Roof bracing requirements. One roof brace is required per 50 m with a minimum of two per ridge line. 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. Rafter spacing rafters must be strong enough to hold the roof sheathing and the shingles. Roof planes less than 6m2 e g.

Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. It allows the bracing requirement to be specified in the construction documents or on the individual truss design drawings. If your local building authority has a rafter spacing code you may not space rafters wider than required by code. Truss bracing requirements are found in section r802 10 3.

This is an area where the code requirements could be improved. 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. The lower roof plan area no soffit 7 040 6 2 8 1 3 1 6 2 3 1 68 7 m. 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.

This section requires trusses to be braced to prevent rotation and to provide lateral stability. Dormers porches do not require bracing. Unless the truss spans 60 feet or more special inspection of the truss web bracing installation is not required. The ceiling joists restrain the exterior walls from being thrust outwards as gravity loads such as snow push down on the roof.