Flat Roof Wooden Beam

Span tables for flat roof joists to bs 5268 7 2 imposed loads of 0 75 kn m for maintenance and snow load are applicable where there is no permanent access no fixed ladder or staircase and most areas where the altitude does not exceed 100 metres refer to bs 6399 3.

Flat roof wooden beam.

For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. A measurement of roof area that equals 100 square feet an area 10 feet by 10 feet. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. It has been my experience to never use a beam smaller than a two ply 2 x 8.

Slope a roof s slope is the number of inches it rises for every 12 inches of horizontal run a roof with a 4 in 12 slope rises 4 inches for every 12 inches of horizontal run. This calculator matches up with 90 of the applications in the 2012 international residential code book. Continuing on from part 3. 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.

Wooden beams attach atop the posts and rafters install between the beams. The size of lumber used depends on the size of. If there is are any questions about anything else then you should contact your supplier or an engineer. Steel is cheaper than wood in most cases and it can handle a load much better but steel beams must usually be cut off site and trucked into a location whereas wood beams can readily be cut on site.

Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. Structures that use steel roof beam construction usually have flat roofs but some smaller structures may have a peaked roof. Let s consider a basic gable wood roof framing design. Most interior beams need to include the roof load.

This is a completion video of a flat roof framing. This is a completion video of a flat roof framing. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. The same roof has a 4 12 or 1 3 pitch.

Floor beam span tables of residential structural design we will now look at roof rafter and beam design.