Hi,
What is the correct placement of exposed fasteners for metal roofing? Are the fasteners placed on the ridges or on the flat surfaces. What is the correct spacing?
Thanks for your advice, PA
Hi,
What is the correct placement of exposed fasteners for metal roofing? Are the fasteners placed on the ridges or on the flat surfaces. What is the correct spacing?
Thanks for your advice, PA
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Replies
Follow manufacturer's recommendation.
I'd never put the screws in the raised ridges....
How many screws? How much wind?
Any jackass can kick down a barn, but it takes a carpenter to build one.
The screws go in between each rib and on the overlap use a stich screw for the ribs.
the screws never goes on top of the rib. because I,m in hurricane area, I did mine every two feet
Not entirely correct.
There are manufacturers who recommend a stitch screw on laps.
Excellence is its own reward!
I hear in the midwest and that's the way it's done here. Around Here the mfg requires that stitch screws go in the rib on panel overlap.
Not sure what a stich screw is, but I've put on a bunch of 5 vee galvanized roofs, and only fasten through the ridges. Lead head nails, neoprene washered nails, screws with neoprene washers and caps. We only fasten in the flats if its over a soffit (not enough room to fasten at the outside ridges). I did two of my own houses this way, too, no leaks that I ever saw. The nails do have to be rebanged everyonce in while 'cause that steel does move.
I've seen galvalume fastened in the flat and on the ridges, don't know how they fared.
The best cap and washer screws I used were from Home Depot (go figure). Sun something brand, I'll see if I can find a bag. The washers seated without distorting unlike ones I've gotten from roofing distributors, but even those haven't leaked. EliphIno!
A stitch screw is a 3/4 to 1 " screw for screwing ribs in panel overlap. It just penetrates the ribs and not the decking or perlens.
the way my roof is. The overlap is on the flat not the ridge
The washers are designed and intended to deform slightly. The cap washer is cupped to contain it and make it become a compression gasket. When it is torqued properly to the steel roof over a solid wood backing the gasket seals against water intrusion.
Placing the lead headed nails on the ridges was necessary because they will loosen up. Less water flows on the ridge than in the valleys or flats so there is less leakage around those loose nails. That practice gets pulled forward into screw installation by those who don't read or understand the instructions for these newer roof systems.
The modern screws can leak when they are torqued down too tight and the pressure fractures the neoprene. Most instalation instructions include a diagram showing the proper tightening, just like cedar shingle sellers provide diagrams showing the proper depth to drive shingle nails to prevent premature splitting.
If you put the screws in the ridges, it is impossible to torque the cap washer onto the neoprene washer enough to seal it without pushing down a little on that ridge and forcing the flats to belly up slightly. This can amke it easier for wind to get lift on the whole system. When that wind waves wrinkles across the roof, those vibrations can loosen the srews that are placed in those ridges.
Learning to place the right screw in the right place with the right amount of torque will make for a longer lasting roof..
Excellence is its own reward!