Metal Roof Screws Leaking - DIY Chatroom

WBNC · 11-06-2009, 02:20 PM

We have a metal roof that is about 10 years old and it was installed by the previous owner. Because of that, the installer will not honor his installation warranty, just the manufacturer's. We discovered a few leaks in the roof and have determined that they are coming from some of the screws on the roof. these are self tapping screws with rubber bushings. the installer wants $1000 to do the job since they must remove the ridge cap, install anchors, replace the ridge cap and then check the screws.

anybody with experience in this area? is this something that the everyday joe could do? i taped a socket wrench to a broom handle and was able to tighten some of the lower ones...

WBNC

tinner666 · 11-06-2009, 06:58 PM

Exposed screws need maintenance. They're gonna let water in around them, even if you can't see it. Until the wood rots in those spots.
Every few years, I believe you'll need to go up 1 screw size and replace them all.
Never use the system myself.

pyper · 11-06-2009, 11:52 PM

I've got a metal roof with screws like you describe.

The roof should have been installed over a waterproof membrane, like felt. If it's not, then it's not on right.

If there's a small leak, it ought to drip off (or worst case down) the screw and hit the felt.

It seems like it should take a long, long, time before the very small amount of water could get past the felt. Mine shows no signs of water on the underside of the roof decking after at least 5 years.

The point of failure is the rubber gasket. Just replace the screws that leak, and don't screw them in so tight.

tinner666 · 11-07-2009, 09:48 AM

Tightness can make some difference. Not much. Listen to the roof installed with exposed fasteners. You can hear it shifting as the metal heats in the morning and trying to find a way to expant between the screws. The metal loosens the screws with all it's movement. The holes around the screws elongate to accomadate the movement.
5 years is a good run without leaks. Bck out a few screws and see if the wood shows signs of dampness yet.

That's why real metal roofs have expansion built into them.

http://www.albertsroofing.com/Tin%20...to_gallery.htm

tomstruble · 11-09-2009, 11:52 PM

those kinda of roofs are usually meant for open purlin ag buildings
not houses

JDM · 11-10-2009, 12:11 PM

Tightening the screws may not actually help, in fact it can make it worse. If you overtighten the screws it can cause them to leak. You need to remove the screws that are leaking now and replace them with #14 oversized roofing screws. You can do the job yourself.

WBNC · 11-10-2009, 12:20 PM

the ones that i can reach i have tightened just a bit. i did not want the busings to mushroom...

pyper · 11-11-2009, 04:09 PM

Quote:

Originally Posted by tomstruble

those kinda of roofs are usually meant for open purlin ag buildings not houses

Screw down metal roofing is becoming very common in the South. It's commonly put over old roofs. In new construction they usually put sheathing on the roof first. Some installers put purlins on top of the sheathing (or old roof) and some don't.

FWIW, my shed has had "5V" metal roofing for 15 or more years (it was there when we bought it). It's open on the bottom, and as far as I can see there are no leaks (I just checked -- the remnants of hurricane Ida just dropped 4 or more inchees of water on us, so if there was a leak it would be easy to spot). It's not even put on with screws, but nails with little neoprene washers.

tomstruble · 11-13-2009, 03:09 AM

just because its becoming common dont mean its the way to do it

the more of these roof you see the more problems your going to see with screws leaking
think about it every one of those thousands of screws have to seal perfectly ,the roof on your shed is the place for that product

a conceled fastener roof for a house imo

pyper · 11-13-2009, 12:19 PM

Quote:

Originally Posted by tomstruble

just because its becoming common dont mean its the way to do it

the more of these roof you see the more problems your going to see with screws leaking
think about it every one of those thousands of screws have to seal perfectly ,the roof on your shed is the place for that product

a concealed fastener roof for a house imo

You make it sound like there's no margin of error on installing the screws.

The fact that my shed, built probably 20 years ago by guys who didn't know what they were doing, still doesn't leak even after 4 inches of rain, suggests otherwise.

Concealed fasteners sound like they'd be superior, but the screw-through systems seem to be fairly robust. How much more does the material for a concealed-fastener roof cost? It's not like we're going to change anything at this point though, but I'm curious. Actually, if I did get a leak from a screw I would probably be tempted to put a dab of silicon caulk on the screw head.

tinner666 · 11-13-2009, 07:05 PM

"Concealed fasteners sound like they'd be superior, but the screw-through systems seem to be fairly robust. How much more does the material for a concealed-fastener roof cost?"
I don't know. Doing residential, I've never had reason to price the exposed fastener system. I'm more into the 'century' roof.
I do get many calls to repair/recaulk/rescrew that type though. Never bothered to bid one. I've been under them often and it's a neat sound to her as the sun starts warming those panels. Little twings, twangs, and other noises abound as the metal tries moving under the strain of expansion. Pretty neat!

pyper · 11-13-2009, 11:15 PM

Quote:

Originally Posted by tinner666

I've been under them often and it's a neat sound to her as the sun starts warming those panels. Little twings, twangs, and other noises abound as the metal tries moving under the strain of expansion. Pretty neat!

I'm under mine all the time as it heats and cools and it doesn't do that. I wonder what the difference is.