Lay the first purlin at the ridge.
Purlins of flat roofs.
Snap a chalk line horizontally across the roof two feet down from the top.
Image copyright belongs to albion sections limited uk roof purlin are members used to directly support roof sheeting materials and could be made of timber or steel.
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.
If you are planning upon going with edgewise purlins across a single truss you are going to run into an uplift problem.
Flat roofs the recent and more onerous requirements of approved document l of the building regulations relating to energy conservation have shifted the emphasis for thermal efficiency from the building structure to the building envelope.
Roof live load roof dead load x spacing x span of purlin 2 divided by.
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.
Purlins 24 spacing mike the pole barn guru writes.
The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.
Illustration shows purlins at 1 2m centres however the maximum purlin centres should not exceed 1 8m.
Purlins placed flat will not span eight feet so eliminates this option.
How to install metal roof purlins.
Trusses most likely on 8 s.