Use these two tables for roof rafters with a slope of 3 in 12 or less.
Roof rafter sizes and spans.
Rafter stock size calculator.
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.
Click the button to calculate the stock size needed for this job.
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 spans are tabulated for the most common roof loads.
2x4 2x6 2x8 2x10 2x12.
Use these two tables for roof rafters with a slope greater than 3 in 12.
3 stud construction standard utility.
Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.
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.
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.
Rafter stock size calculator.
Area span on the flat.
The above spans are based on american softwood lumber standard sizes.
1 psf lb f ft 2 47 88 n m 2.
1 in 25 4 mm.
Live load 20 lbs ft 2 956 n m 2.
More roof calculators roof truss calculator how to cut rafters.
This calculator is to be used as an estimating tool only.
The lengths and sizes of joists vary depending on the species and quality of the lumber used.
1 ft 0 3048 m.
Click the button to calculate the stock size needed for this job.
This is based upon the span of the rafter horizontal span not total rafter length live and dead loads.
2 are indicated below.
The loads are based on adjusted roof snow loads from the governing building code.
Structures such as sheds or barns can be frames with rafters every 24 again make sure to consult local codes.
Dead load weight of structure and fixed loads 15 lbs ft 2.
This rafter span calculator is species specific for douglas fir hemlock etc.
For additional species of lumber check out the rafter span calculator from the american wood council website.
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.
Floor joists ceiling joists rafters snow load rafters roof live load deflection limit.
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.
Input the rafter span on the flat eave overhang and pitch of the roof.
L 720 l 600 l 480 l 360 l 240 l 180.
