Wood Purlin Flat Roof

Or less x 1 1 cfu the flat use factor for applying the load to the wide face of a member.

Wood purlin flat roof.

Roof purlin are members used to directly support roof sheeting materials and could be made of timber or steel. Dead load weight of structure and fixed loads 15 lbs ft 2. Live load is weight of furniture wind snow and more. The inspector asked about the type of wood being used as purlins.

1 ft 0 3048 m. I have extra wood so i did plan on adding a short chunk of 2 4 on trusses where the purlins meet on the single board. I planned on using 2 4 purlins flat to cover the gaps and secure the roof to that. For relatively flat roofs slope less than 3 12 the joists and rafters have to be designed as beams.

I explained the layout of roof trusses and purlins on your building design. Flat use factor c fu 1 nds supplement table 4a c i. 1 psf lb f ft 2 47 88 n m 2. Roof ceiling framing general roofs 3 12 members supporting joists and rafters designed as beams notches holes controlled joists rafters supported laterally a few general comments here about the irc requirements.

Do all roofing projects require purlins. The purlin are ultimately used to fasten the roof steel providing a diaphragm effect along with the siding when properly engineered and installed. 2 are indicated below. Insert two equally spaced nails into the rafter.

8 x section modulus of a 4 2 of 1 3125 x fb fiberstress in bending x 1 15 duration of load x 1 15 cr repetitive member factor as the purlins are spaced 24 o c. Then i plan on using a double 2 10 for a header and spacing my trusses every 4 feet. Snap a chalk line horizontally across the roof two feet down from the top. Purlins are dimensional lumber that are fastened to the top chord of trusses connecting them together for bracing purposes.

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. Fasten the purlin with 16d common nails into each vertical rafter. Lay the first purlin at the ridge of the roof down to the chalk line beginning at either corner. One on the post and the next on the header.

Purlins are non pressure treated 1 x 4 x 12 lumber that is installed on to the roof in a specific layout pattern and screw pattern. Roof live load roof dead load x spacing x span of purlin 2. He gave me a copy of r802 5 1 3 rafter spans for common lumber species. The roof support system is a ridgepole and either rafters which run perpendicular from the top of the walls to the ridge or purlins which run parallel to the ridge.

I did not know.