Roof Rafter Sizes And Spans

Floor joists ceiling joists rafters snow load rafters roof live load deflection limit.

Roof rafter sizes and spans. Live load is weight of furniture wind snow and more. Rafter spans are tabulated for the most common roof loads. Click the button to calculate the stock size needed for this job. 1 in 25 4 mm.

Input the rafter span on the flat eave overhang and pitch of the roof. If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center. To size joists and rafters use the maximum span tables for southern yellow pine. Rafter and joist span faq.

Spacing in 12 16 19 2 24. Dead load weight of structure and fixed loads 15 lbs ft 2. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Use these two tables for roof rafters with a slope greater than 3 in 12.

2 are indicated below. Input the rafter span on the flat eave overhang and pitch of the roof. 1 ft 0 3048 m. This calculator is to be used as an estimating tool only.

2x4 2x6 2x8 2x10 2x12. Live load 20 lbs ft 2 956 n m 2. The loads are based on adjusted roof snow loads from the governing building code. For roof live loads less than 20 pounds per square foot psf rafter spans and required e values tabulated for 20 psf shall be permitted to be adjusted in accordance with the fol lowing table.

This rafter span calculator is species specific for douglas fir hemlock etc. 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. Use these two tables for roof rafters with a slope of 3 in 12 or less. The above spans are based on american softwood lumber standard sizes.

Rafter stock size calculator. It is always better to have a large rafter rather than be concerned with a sagging roof. Area span on the flat. This is based upon the span of the rafter horizontal span not total rafter length live and dead loads.

More roof calculators roof truss calculator how to cut rafters. For additional species of lumber check out the rafter span calculator from the american wood council website. 3 stud construction standard utility. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.

Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. Click the button to calculate the stock size needed for this job. Rafter stock size calculator. This calculator is to be used as an estimating tool only.

1 psf lb f ft 2 47 88 n m 2.