What Size Lumber For Roof Rafters

Here the wall thickness is 240 57 inches.

What size lumber for roof rafters. The lengths and sizes of joists vary depending on the species and quality of the lumber used. This is based upon the span of the rafter horizontal span not total rafter length live and dead loads. Maximum rafter spans for a patio roof. Dead load weight of structure and fixed loads 15 lbs ft 2.

Live load is weight of furniture wind snow and more. Rafter spacing and roof length will be used to determine quantity of rafters needed for your project. For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine. It is always better to have a large rafter rather than be concerned with a sagging roof.

1 psf lb f ft 2 47 88 n m 2. If you re building rafters and aren t sure where to start when determining the length of your lumber you re in the right place our rafter stock size calculator shows you how long your rafters should be so you ll know what you need in terms of framing lumber dimensional lumber studs and more. Rafter and joist span faq. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.

To size joists and rafters use the maximum span tables for southern yellow pine. Just enter the dimensions of the roof rise and run to get started. 1 ft 0 3048 m. In addition using the rafters diagram you can see the precise dimensions of the roof rafter including length from every possible angle.

2 are indicated below. Once all of these inputs have been entered into the calculator you will see that the appropriate rafter width is 120 33 inches. Trying to find what size lumber to use. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.