Roof Truss Span Distance

These standards are as follows.

Roof truss span distance.

For example a roof with a span of 20 ft and a rise of 7 feet needs rafters that are the square root of 400 49 21 2 feet. After the braces are in place you will mark the distance from the edge of the building to where you would like to attach your first truss. For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. C rafter length.

This means that if you re in charge of repairing or installing roofing trusses you ll be expected to hold to these standards. Already having the rise will make it easy to determine the rafter length by loading the numbers into the equation chart. Bt b tc 6 6 common truss configurations for the most widely designed roof shapes. Overhang this is the extra part that extends beyond the exterior wall of the home.

To achieve maximum indicated spans trusses may require six or more panels. Standard roof truss spacing. Contact your localalpine trussmanufacturerorofficeformoreinformation. Equation a2 b2 c2.

Typical roof truss. For instance if you are spacing your trusses 18 inches apart make a mark 18 inches from the edge. Mono used where the roof is required to.