Roof Rafter Sizes And Spans

Rafter stock size calculator.

Roof rafter sizes and spans.

The above spans are based on american softwood lumber standard sizes. Use these two tables for roof rafters with a slope greater than 3 in 12. Floor joists ceiling joists rafters snow load rafters roof live load deflection limit. Click the button to calculate the stock size needed for this job.

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. 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.

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. Dead load weight of structure and fixed loads 15 lbs ft 2. Area span on the flat. 2 are indicated below.

Spacing in 12 16 19 2 24. 1 in 25 4 mm. Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes. More roof calculators roof truss calculator how to cut rafters.

It is always better to have a large rafter rather than be concerned with a sagging roof. The lengths and sizes of joists vary depending on the species and quality of the lumber used. This calculator is to be used as an estimating tool only. To size joists and rafters use the maximum span tables for southern yellow pine.

3 stud construction standard utility. 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. This calculator is to be used as an estimating tool only.

2x4 2x6 2x8 2x10 2x12. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Live load is weight of furniture wind snow and more. Live load 20 lbs ft 2 956 n m 2.

Rafter spans are tabulated for the most common roof loads. 1 psf lb f ft 2 47 88 n m 2. Rafter stock size calculator. Rafter and joist span faq.

Click the button to calculate the stock size needed for this job. 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. 1 ft 0 3048 m. This rafter span calculator is species specific for douglas fir hemlock etc.

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