How To Size Roof Ridge Beam

Determining the ridge beam height.

How to size roof ridge beam.

Here s a picture of a gable style shed using a ridge beam. It has been my experience to never use a beam smaller than a two ply 2 x 8. 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. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.

Ridge beams are required by code if the roof slope is less than 3 in 12 irc section r802 3. This tells you the size of the beam needed to support the porch s roof. 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 means the example porch would need a 6 inch by 8 inch beam.

Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam. Framing in a ridge beam in shed roof construction is not hard. I always always build trusses. The finished ridge beam height z above the top of the wall will be m plus the y height.

This calculator matches up with 90 of the applications in the 2012 international residential code book. In the example d calculates to 7 75. Calculate the initial value for d then round it up to the nearest inch. Most interior beams need to include the roof load.

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. A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads. 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.