You will find differing opinions on this topic and they will vary between manufacturers. The only way to not void a warranty potentially is to do it according to that manufacturer's requirements.
I feel that installing in the flats is a lot more foolproof.
Todd Miller
2013-12-26 10:33:40.000000
Fasteners are increasing in quality on a regular basis but certainly we have seen that be necessary in some cases.
Todd Miller
2014-01-13 19:17:46.000000
I have found conflicting arguments for fastening corrugated metal roofing. David Keener of Fabral, (and others) says the "screws should always be installed in the flat of panels" so there is a solid seat and proper compression of the screw's neoprene washer. According to Journal of Light Construction, Henry Spies, "always fasten through the ridges". Chad Taylor, experienced Florida roofer says "we have had good success for years with screwing at the top of the ribs. I feel there is less chance for leaks if the holes in the metal are at the high points rather than the low points of the panel."
My thinking is; the valleys are where the water is, so you don't want the fastening hole there. By placing a neoprene spacer under a ridge fastener would prevent the metal from deflecting and provide proper seating of the screw's neoprene washer. However, I don't want to void a manufactures warrenty by not installing to their instructions. I seek your advise.
Robert Cambridge
2013-12-26 10:20:58.000000
I've been told that the fasteners (neoprene gaskets) must be replaced around fifteen years. True or false?