Roof Beam Size

In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.

Roof beam size. Tables providing size selections for various beam spans and loading combinations for southern pine dimension lumber and southern pine glued laminated timber are available for the following applications. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. The finished ridge beam height z above the top of the wall will be m plus the y height. Window door garage door headers supporting roof loads only.

For heavy roofs or in. If you know the slope x in 12 you want to use for your roof framing design you can use it along with the run r to determine the height of the ridge beam for example if the slope is 4 in 12 and the run is 12 feet the ridge beam height m will be 4 feet. Most interior beams need to include the roof load. Maximum rafter spans for a patio roof.

Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. In the example d calculates to 7 75. It has been my experience to never use a beam smaller than a two ply 2 x 8. This means the example porch would need a 6 inch by 8 inch beam.

Window door garage door headers supporting roof wall floor loads. Calculate the initial value for d then round it up to the nearest inch. If there is are any questions about anything else then you should contact your supplier or an engineer. Determining the ridge beam height.