Metal Roof Screws In Ridge Or Flat

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.

Metal roof screws in ridge or flat.

The directions for installing metal roofing panels that are attached by exposed fasteners give different methods for nails vs screws. Your roof will have thousands of screw holes. It depends on the metal if it is coretin or any other corrugated metal no screws in the valley or flat part of metal if it is a tuffrib or deltarib put screws in the valley. The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to.

These panels have raised ribs. As the screws are driven the washer presses against the metal roofing to form a water proof seal. The main cause of a leaking roof on a diy metal roofing installation is incorrectly fastening the screws. Quite often the screws are over tightened or under tightened and when this happens it creates leak points.

Having done several metal roofs since then i would say if you are an amateur screw on the flat with 1 1 2 screws. Screwing high on the rib is difficult for the amateur. My natural inclination would be to insert fasteners through the top of the rib so that the hole. I strap all roofs with nothing less than 2 4 to help lock that roof in place.

If the screws are driven correctly fastening through either the valleys or the ridges of the roofing is considered acceptable in this country. If you live in a snow area this will help with ice and snow sheering screws of and me coming to fix your new roof. Valid arguments can be made for both preferences. We do recommend it however.