The manufacturers recommend screws in the valley 3 per perling and shorter screws spaced 18 to 24 inches depends on the manufacturer on the ridges.
Roofing screws in the ridge or flat.
On the ridges can distort the metal.
The main cause of a leaking roof on a diy metal roofing installation is incorrectly fastening the screws.
The idea being that the longer screws in the valley hold the sheet down and the shorter screws on the ridges keep the wind from picking up the sheet.
Metal moves some heat cold expansion and makes a bigger hole in metal for a leak.
Screwing or fastening down a metal roof is one of the easiest parts of a metal roofing installation but it s also the most problematic.
Screwing high on the rib is difficult for the amateur.
250 brown 12 x 1 1 2 hex regrip sheet metal roof screw.
As the screws are driven the washer presses against the metal roofing to form a water proof seal.
Place large tab closure between the ridge cap and the roof panels.
Screws in the flat nails on the ridge.
Make sure to screw through closures.
Attach ridge cap to rib of roof panel with screws on every rib along both sides of rib.
Quite often the screws are over tightened or under tightened and when this happens it creates leak points.
If the screws are driven correctly fastening through either the valleys or the ridges of the roofing is considered acceptable in this country.
Make sure and not get them too tight don t squish the rubber gasket just nice and snug.
Your roof will have thousands of screw holes.
I strap all roofs with nothing less than 2 4 to help lock that roof in place.
Sharp point metal to wood siding screws.
4 6 out of 5 stars 10.