Roof Rafter Spacing 2x4

If your local building authority has a rafter spacing code you may not space rafters wider than required by code.

Roof rafter spacing 2x4.

Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. Both of these are for light roof loads. 1 ft 0 3048 m. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.

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. As mentioned above a 2 4 spf shed roof rafter can span 11. 2 are indicated below. Rafters must be strong enough to hold the roof sheathing and the shingles.

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. Live load is weight of furniture wind snow and more. Spacing in exterior exposure. Dead load weight of structure and fixed loads 15 lbs ft 2.

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. An syp rafter can span 11. But they do tend to space rafters in one of several industry standard increments typically either 12 16 or 24 inches apart. Rather than having 2 4 purlins every 12 it would make far more sense economically to use 2 6 purlins every 24.

Span calculator for wood joists and rafters also available for the. There is no standard spacing it depends on what size of rafters you want to use and the span of your shed. 1 psf lb f ft 2 47 88 n m 2. Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches.

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. For instance 2 grade 2x4s at 16 on center will span just over 9. It is always better to have a large rafter rather than be concerned with a sagging roof. For standard shed roof rafter spacing see rafter span chart.