Flat Roof Rafter Span

Input the rafter span on the flat eave overhang and pitch of the roof.

Flat roof rafter span.

Click the button to calculate the stock size needed for this job. Wood beam calculator american wood council website rafter and joist span faq. 2 4 rafters can span up to 7. 1 psf lb f ft 2 47 88 n m 2.

Also available for the android os. 1 ft 0 3048 m. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no. Live load overhang kpa.

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. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. 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.

1 in 25 4 mm. Loads are calculated in accordance with table 3 1 of as nzs 1170 1 2002. The 1 grade. The rafters in a flat roof serve as ceiling joists for the space below.

The tables below give maximum spans for rafters and beams. 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. Most roof framing is 24 on center and you can still build sheds up to 14 with 2 4 rafters at 24 on center.

2 are indicated below. Input the rafter span on the flat eave overhang and pitch of the roof. Dead load weight of structure and fixed loads 15 lbs ft 2. Use these two tables for roof rafters with a slope greater than 3 in 12.

This calculator is to be used as an estimating tool only. For heavy loads 2x4s can span up to 5. This is set by the roof use you selected in the previous screen and cannot be modified. Live load is weight of furniture wind snow and more.

The size of rafters for a flat roof depends on the horizontal span of the building the type and grade of timber used and the load on the roof. Rafter span tables use these two tables for roof rafters with a slope of 3 in 12 or less. Live load 20 lbs ft 2 956 n m 2. Rafter stock size calculator.

The imposed uniformly distributed live load in the main span. Span calculator for wood joists and rafters also available for the android os. For light load roofs 24 o c.