This sizing guide for roof rafters will help determine what you need for your small project.
Ridge beam size roof framing.
Most interior beams need to include the roof load.
If there is are any questions about anything else then you should contact your supplier or an engineer.
Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.
Ridge beam sizing is based on the span of the beam between supports and the amount of roof load supported by the beam.
It has been my experience to never use a beam smaller than a two ply 2 x 8.
Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.
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.
Collar ties rafter ties tension beams structural ridge beams.
Its the way i was trained to build sheds.
Determining the ridge beam height.
A ridge board is a non structural member that serves as a prop for opposing rafters to rest against and connect to.
Framing in a ridge beam in shed roof construction is not hard.
Some of these can support the roof and prevent ridge sagging and wall spreading.
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.
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.
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 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.
Here s a picture of a gable style shed using a ridge beam.
You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths.
There are several variables to consider when determining the proper rafter size.
This calculator matches up with 90 of the applications in the 2012 international residential code book.
I always always build trusses.
