Shed Roof Purlin Size

Wide span sheds then offered an experienced builder to oversee the erection of the new components at our own costs.

Shed roof purlin size.

Because this style of a shed has a flat roof it can facilitate a wider overhang which is ideal for storage. Hi i am putting a pitched roof over my mobile home. They are installed on top of the roof rafters with a felt underlayment or vapor barrier installed on top. Check for gravity loads.

Load duration factor c d 1 15 nds 2 3 2 c m. Roof pitch between 15 and 22 5 degrees with rafter spacing strength class c16 size of rafters in mm 400mm 450mm 600mm. The rule of thumb is that the gusset should be twice the width of the wood you use for your rafters. Purlins are 2 by 4 feet and are installed much like metal roofing.

The common 4 on center design is suitable for snow loads up to 60 for most applications. Dead load will be the actual weight of the roof steel and the roof purlins. Despite the fact that it was found that wide span sheds were not at fault the directors paid for the new steel components to be supplied at our costs only to be reimbursed if there was a successful insurance claim. Total purlin dead load 1 638 psf.

So roughly 7 8 long for a 2 4. Purlin plates are beams which support the mid span of rafters and are supported by posts. The size of the roof overhang you choose depends largely on the style of your shed s roof. Temperature factor c t 1 nds 2 3 3.

With a flat shed roof the roof simply extends past the wall plate to provide an overhang. Bending stresses f b. 20 psf x 949 1 5 psf x 12 x 949 x 11 625 2 8 x 3 0625 x 1 15 x 1 15 972 75 psi. Wet service factor c m 1 because purlins are protected from moisture by roof c t.

A purlin plate in wood construction is also called an arcade plate in european english under purlin and principal purlin. You are going to cut out triangles that will cover the apex of each set of rafters. Allowable bending pressure f b f b c d c m c t c l c f c fu c i c r c d. Metal roof purlins are installed horizontally under metal roofs.

Exterior paneling and all exterior sidings what size for purlins. For sake of discussion we will assume a minimal roof snow load of 20 psf pounds per square foot and a 4 12 roof slope. By supporting the rafters they allow longer spans than the rafters alone. Higher snow loads and larger spans will require purlins to be spaced closer together than 24 on center in the drift area.

My rafters are 2x6 ridge beam is 2x8 collar ties 2x6. For snow loads exceeding 60 trusses are recommended to be closer together. Engineers calculate this on a job site basis. For an 8 10 shed one sheet of plywood should be fine.