Roof Bracing Requirements

Dormers porches do not require bracing.

Roof bracing requirements.

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. Rafter spacing rafters must be strong enough to hold the roof sheathing and the shingles. This is an area where the code requirements could be improved. Unless the truss spans 60 feet or more special inspection of the truss web bracing installation is not required.

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. I roof plane brace or. The bracing described in this brochure covers both framed roofs and fully trussed roofs. Roof braces can consist of either.

Truss bracing requirements are found in section r802 10 3. Roof planes less than 6m2 e g. The ceiling joists restrain the exterior walls from being thrust outwards as gravity loads such as snow push down on the roof. 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. If your local building authority has a rafter spacing code you may not space rafters wider than required by code. It allows the bracing requirement to be specified in the construction documents or on the individual truss design drawings. Truss web bracing is critical to the stability of the roof system yet very few residential projects have engineering observation of completed roof systems.