While your beam size ultimately depends on design factors such as whether you include a covered roof structure or open lattice strips a familiarity with conventional beam spans gives you an idea of how far apart you can space your posts.
Shed roof beam.
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.
Wood beam calculator american wood council website rafter and joist span faq.
When to use common rafters.
Sunbelt rack s structural steel i beam cantilever rack can function as the building blocks of our t sheds l sheds and drive thru buildings or as a stand alone multi level high density storage system for long length materials.
However our instructions include making shed rafters with a ridge beam.
Here s a picture of a gable style shed using a ridge beam.
For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine.
Framing in a ridge beam in shed roof construction is not hard.
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.
If one side of the roof is supported by the house and the other side is supported by the beam divide the total load by two as the beam is only supporting half of the roof.
Building trusses on site is easily done for a shed.
Once the rafter trusses are secure cover them with plywood sheathing to support the shingles.
Divide the total load according to how many supporting beams the roof will have.
The smallest beams for patio covers are typically 4 by 6.
I always always build trusses.
Roof pitch and corresponding angle of degree.
If there is also a beam in the middle of the roof divide the total load by three.
A ridge beam runs the length of the shed roof connecting every pair of rafters.
The lengths and sizes of joists vary depending on the species and quality of the lumber used.
Then assemble your rafter halves into trusses using plywood gusset plates and attach the end rafters to your shed frame.
If you have to go with a roof pitch less than 3 12 then it would either have to be a metal roof or a roof covered with a rubber membrane to prevent water penetration.
A simple gable shed roof is often built using 2 4 or 2 6 lumber for the rafters and 2 4 for the collar ties.
The rafters are angle cut at the ridge end and notched with a birdsmouth where it meets the top plate of the supporting wall.
The 1 grade.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.