How Far Apart Are Trusses In A Flat Roof

Flat the most economical flat truss for a roof is provided when the depth of the truss in inches is approximately equal to 7 of the span in inches.

How far apart are trusses in a flat roof. Hi i saw on your webpage the pole barn guru stated the trusses could be spaced 12 apart i called and was told it is a double truss one on each side of a post that is on 12 centers. It all comes down to engineering. We suggest 5 on center trusses with flat purlins to be restricted to 30 ground snow loads or less in most instances. The tables below give maximum spans for rafters and beams.

Their defense is our engineers will not allow us to. The higher the snow load the closer the purlin spacing required. Therefore if you want a 10 12 single sloped roof and you live in a heavy snow area then you can space your rafters 16 apart and use spf 2 6 lumber. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.

Truss spacing for metal roof. Spf 2 6 rafters can span 8. Reader dave in michigan writes. If you move the rafters closer together at 16 o c then your syp rafters will span 11 and spf up to 10.

These standards are as follows. Putting the trusses into place. Most are spaced between 18 26 inches apart. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.

If purlins are laying flat on top of the truss 5 or 6 feet is the max on 2x4 s edge up can go to 12 feet or more. With this design change roof trusses could be placed 12 feet apart making it possible for roofs to support the loads to which they would be subjected. I ve had roof truss manufacturers try to convince me it is impossible to place wood trusses at spacings of over every 4 feet. Typical roof truss spacing means that they are usually about 24 inches from centre which means at the centre of one truss there will be a two foot gap or twenty four inch gap until the centre of the next truss.

Common spacing for trusses on this type of building is often between 2 and 4 feet but trusses built with advanced designs may allow spacing as great as 8 or 12 feet. That is exactly what i have double trusses on each side of a post on 12 centers. Most economical when the difference in slope between the top and bottom chords is at least 3 12 or the bottom chord pitch is no more than half the top chord pitch. Once you ve calculated the number of trusses you will need you should purchase the lumber.

The figures are based on quality materials.