Steel Roof Rafter Load Rating

1 psf lb f ft 2 47 88 n m 2.

Steel roof rafter load rating.

Ceiling joist span use this table to determine the maximum lengths of ceiling joists based on species of lumber joist spacing and joist size. Roofs are under a lot of pressure. If your roof is 1 000 square feet the total snow load is 15 000 pounds of snow. Live load psf dead load psf span calculator for wood joists and rafters available for the iphone.

Dead load weight of structure and fixed loads 15 lbs ft 2. Rafter spans can be extended slightly beyond what the rafter tables suggest when there is a cantelever extending beyond the supporting wall. This truss load table guide illustrates how to read allowable load ratings for aluminum and steel truss. The dead load on the bottom chord.

In order to stay intact and in place a roof must be able to resist loads both permanent and temporary that are pushing. 2 are indicated below. If the bottom chord of a roof truss functions as a floor joist such as in an attic room it carries a live load that also varies by use but a typical live floor load for a residential space is about 40 pounds per square foot. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run.

The explanations below will help you determine the appropriate truss to use for your application or conditions based on allowable load ratings. Load limits on the roof of a building. 1 ft 0 3048 m. Consult local building codes for snow load capacity and reference the span tables for joists and rafters published by the american wood council awc as a general rule roofs that have a high human occupancy rate should be framed with rafters every 16 structures such as sheds or barns can be frames with rafters every 24.

Span calculator for wood joists and rafters also available for the android os. If you live in the us our snow load calculator compares the total weight on your roof with the permissible load calculated according to the standards issued by the american society of civil engineers regarding the minimum design loads for buildings and other structures asce7 16. If the snow weighs 10 pounds per cubic foot and there are 1 5 feet on the roof each square foot of the roof is getting 15 pounds of pressure. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.

Live load is weight of furniture wind snow and more.