Spacing in 12 16 19 2 24.
Roof rafter sizes and spans.
Use these two tables for roof rafters with a slope greater than 3 in 12.
For additional species of lumber check out the rafter span calculator from the american wood council website.
1 in 25 4 mm.
It is always better to have a large rafter rather than be concerned with a sagging roof.
To size joists and rafters use the maximum span tables for southern yellow pine.
This calculator is to be used as an estimating tool only.
This rafter span calculator is species specific for douglas fir hemlock etc.
Live load 20 lbs ft 2 956 n m 2.
Rafter stock size calculator.
Click the button to calculate the stock size needed for this job.
The above spans are based on american softwood lumber standard sizes.
This calculator is to be used as an estimating tool only.
L 720 l 600 l 480 l 360 l 240 l 180.
1 psf lb f ft 2 47 88 n m 2.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
Click the button to calculate the stock size needed for this job.
Floor joists ceiling joists rafters snow load rafters roof live load deflection limit.
1 ft 0 3048 m.
This is based upon the span of the rafter horizontal span not total rafter length live and dead loads.
Use these two tables for roof rafters with a slope of 3 in 12 or less.
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.
2x4 2x6 2x8 2x10 2x12.
2 are indicated below.
The loads are based on adjusted roof snow loads from the governing building code.
Area span on the flat.
Live load is weight of furniture wind snow and more.
3 stud construction standard utility.
If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
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.
Rafter and joist span faq.
Rafter spans are tabulated for the most common roof loads.
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.
Input the rafter span on the flat eave overhang and pitch of the roof.
Input the rafter span on the flat eave overhang and pitch of the roof.
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.
The lengths and sizes of joists vary depending on the species and quality of the lumber used.
