Roof Rafter Spacing 2x4

Without even running the calculations i would say there is a good chance the 2 4 purlins will not make the deflection criteria required for a roof framing member supporting steel.

Roof rafter spacing 2x4.

There is no standard spacing it depends on what size of rafters you want to use and the span of your shed. Builders aren t bound by standard rafter spacing measurements. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. 2 are indicated below.

Rafters must be strong enough to hold the roof sheathing and the shingles. Rather than having 2 4 purlins every 12 it would make far more sense economically to use 2 6 purlins every 24. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. An syp rafter can span 11.

Live load psf dead load psf span calculator for wood joists and rafters available for the iphone. 1 psf lb f ft 2 47 88 n m 2. Live load is weight of furniture wind snow and more. Both of these are for light roof loads.

Spacing in exterior exposure. Span calculator for wood joists and rafters also available for the. Dead load weight of structure and fixed loads 15 lbs ft 2. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.

If you live in an area that requires a shed roof rafter to support a heavy load then an spf rafter can only span 7. Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches. It is always better to have a large rafter rather than be concerned with a sagging roof. As mentioned above a 2 4 spf shed roof rafter can span 11.

For standard shed roof rafter spacing see rafter span chart. For instance 2 grade 2x4s at 16 on center will span just over 9. 1 ft 0 3048 m. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.