Lumber Size For Roof Rafters

Therefore if you want a 10 12 single sloped roof and you live in a heavy snow area then you can space your rafters 16 apart and use spf 2 6 lumber.

Lumber size for roof rafters.

If you move the rafters closer together at 16 o c then your syp rafters will span 11 and spf up to 10. 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. Input the rafter span on the flat eave overhang and pitch of the roof. 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.

Live load is weight of furniture wind snow and more. Live load 20 lbs ft 2 956 n m 2. 2 are indicated below. Rafter and joist span faq.

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. This rafter span calculator is species specific for douglas fir hemlock etc. 1 psf lb f ft 2 47 88 n m 2. Dead load weight of structure and fixed loads 15 lbs ft 2.

If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. Spf 2 6 rafters can span 8. Just enter the dimensions of the roof rise and run to get started. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.

Lumber size width 2x8 2x10 or 2x12 boards will be used to estimate cost of each rafter as well as total cost excluding local sales tax. This calculator is to be used as an estimating tool only. Rafters longer than 20 feet. To size joists and rafters use the maximum span tables for southern yellow pine.

This is based upon the span of the rafter horizontal span not total rafter length live and dead loads. Home improvement stores do not sell pine boards longer than 20 feet. Rafter spacing and roof length will be used to determine quantity of rafters needed for your project. More roof calculators roof truss calculator.

1 in 25 4 mm. Trying to find what size lumber to use. The lengths and sizes of joists vary depending on the species and quality of the lumber used.