How To Size Roof Ridge Beam

This tells you the size of the beam needed to support the porch s roof.

How to size roof ridge beam.

Framing in a ridge beam in shed roof construction is not hard. Because a ridge beam often carries a significant area of roof load they can exhibit structural distress due to a defect in wood impact on the roof or use of an undersize beam. Ridge beams are required by code if the roof slope is less than 3 in 12 irc section r802 3. A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to.

The ridge beam shown below at the living room of a 1950s modern style ranch house in gainesville has cracked at mid span and is slowly heading towards failure after. Most interior beams need to include the roof load. It has been my experience to never use a beam smaller than a two ply 2 x 8. Here s a picture of a gable style shed using a ridge beam.

Now if you have done any looking around this site you ll quickly see that i am not a fan of using a ridge beam in shed construction. The finished ridge beam height z above the top of the wall will be m plus the y height. Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.

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. This calculator matches up with 90 of the applications in the 2012 international residential code book. Determining the ridge beam height. I always always build trusses.

Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. This means the example porch would need a 6 inch by 8 inch beam. In the example d calculates to 7 75. Ridge beams and boards modern raising ceiling joists jlc technical steico construction roof rafter collar tie calculations structural ridge beamtimber steel framing manual single span ridge beamglulam ridge beam span table elcho.