Roof Rafter Sizes And Spans

L 720 l 600 l 480 l 360 l 240 l 180.

Roof rafter sizes and spans.

1 psf lb f ft 2 47 88 n m 2. For additional species of lumber check out the rafter span calculator from the american wood council website. 1 ft 0 3048 m. 3 stud construction standard utility.

Input the rafter span on the flat eave overhang and pitch of the roof. Live load is weight of furniture wind snow and more. 1 in 25 4 mm. Area span on the flat.

This calculator is to be used as an estimating tool only. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Rafter stock size calculator. Click the button to calculate the stock size needed for this job.

This calculator is to be used as an estimating tool only. Floor joists ceiling joists rafters snow load rafters roof live load deflection limit. Rafter spans are tabulated for the most common roof loads. Spacing in 12 16 19 2 24.

The loads are based on adjusted roof snow loads from the governing building code. Live load 20 lbs ft 2 956 n m 2. The above spans are based on american softwood lumber standard sizes. Rafter stock size calculator.

The lengths and sizes of joists vary depending on the species and quality of the lumber used. 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. Click the button to calculate the stock size needed for this job. More roof calculators roof truss calculator how to cut rafters.

To size joists and rafters use the maximum span tables for southern yellow pine. It is always better to have a large rafter rather than be concerned with a sagging 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. 2x4 2x6 2x8 2x10 2x12.

Use these two tables for roof rafters with a slope greater than 3 in 12. 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. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. An essential part of planning a patio roof or gazebo project is determining the number size and spacing of rafters beams and posts according to the loads they will carry.

Input the rafter span on the flat eave overhang and pitch of the roof. 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. Rafter and joist span faq. Dead load weight of structure and fixed loads 15 lbs ft 2.

This is based upon the span of the rafter horizontal span not total rafter length live and dead loads.