Roof Rafter Spacing 2x4

For instance 2 grade 2x4s at 16 on center will span just over 9.

Roof rafter spacing 2x4.

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. Rather than having 2 4 purlins every 12 it would make far more sense economically to use 2 6 purlins every 24. Dead load weight of structure and fixed loads 15 lbs ft 2. It is always better to have a large rafter rather than be concerned with a sagging roof.

If your local building authority has a rafter spacing code you may not space rafters wider than required by code. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Spacing in exterior exposure. Typical rafter spacing codes will specify a minimum spacing of 16 inches 19 2 inches or 24 inches.

Rafters must be strong enough to hold the roof sheathing and the shingles. 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. 1 psf lb f ft 2 47 88 n m 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.

Live load psf dead load psf span calculator for wood joists and rafters available for the iphone. An syp rafter can span 11. 1 ft 0 3048 m. There is no standard spacing it depends on what size of rafters you want to use and the span of your shed.

Both of these are for light roof loads. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. 2 are indicated below. As mentioned above a 2 4 spf shed roof rafter can span 11.

If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. But they do tend to space rafters in one of several industry standard increments typically either 12 16 or 24 inches apart. For standard shed roof rafter spacing see rafter span chart. 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.