Replacement metal roof....best method

[Rockbadchild]

metal screws seem to have about a 10 year life span before heat and UV exposure makes them start leaking.

I beg to differ on this one. I’ve got some screws I put on a purloin metal roof from 1990 ish . I pulled that old garage down in 2018 and aside from some minor surface rust they were fine. The seals had no cracking and were still soft.
i wouldn’t use them on a house but they are still there waiting for the next shed I build. These were plain galvanized with a plain unpainted galvanized roof.

I have seen them unscrewing by the tin vibration from the rains, and yes crack sealed. but 10 sound pretty conservative.

 

[2manyrocks]

Maybe there are differences in quality of the seals? Regardless, I would think that a standing seam roof could last 50 years?

 

[stumblinhorse]

Mine is the installed the same as @jyoutz, bought 24 gauge metal with exposed fasteners.

So far so good. I’ll update in 40 years.

 

[Rockbadchild]

Maybe there are differences in quality of the seals? Regardless, I would think that a standing seam roof could last 50 years?

not sure by the quality of the screws/seals but if you keep a eye on the screws/ regular maintenances or replacements and don't care about discoloration or paint flaking a metal roof last for ever.

 

[2manyrocks]

I hope you are right because I had a metal roof installed about two years ago, but we used domed headed metal screws. The head of the washer is partly covered by a dome. I'm hoping that will extend their life. But I have not been impressed with the seals on regular metal roof screws.

 

[D&D]

metal screws seem to have about a 10 year life span before heat and UV exposure makes them start leaking.

I beg to differ on this one. I’ve got some screws I put on a purloin metal roof from 1990 ish . I pulled that old garage down in 2018 and aside from some minor surface rust they were fine. The seals had no cracking and were still soft.
i wouldn’t use them on a house but they are still there waiting for the next shed I build. These were plain galvanized with a plain unpainted galvanized roof.

We use the screws that have a formed cap covering the gasket.

https://www.fastenersplus.com/cdn/shop/products/ZXL-WOODBINDER.collen.Galvanized.1-inch.01.jpg?v=1594908726

 

[2manyrocks]

That is the style of metal screw we used, but I don't know which brand they were.

 

[Fuddyduddy1952]

This past summer I had standing seam metal roof installed on house. Although only one layer of shingles as mentioned they removed them down to plywood. I had two skylights which they removed, covered with plywood. Although skylights looked fine the wood below flashing had started to deteriorate (installed 30 years ago). Then we saw all was well and they put down insulation then metal. New 6" gutters/downspouts with a type of leaf guard.
Now snow or leaves slides right off.
Screw down metal would have been half price and I have that on horse barn & garages, no leaks.

 

[CH4Ohio]

We replaced our roof in November. Talked to a half dozen contractors and got prices for both metal and asphalt.

The approach was the same by all of them. Tear off the existing shingles, put down underlayment with ice barrier being used in the valleys and at the bottoms, and then metal or shingles go down right on the underlayment. Absolutely no purlins.

This was for standing seam metal roofing with hidden fasteners. No one priced barn roofing with rubber-grommet screws, but of course I didn't ask for that either. I don't think any roofer would guarantee a roof NOT to leak using barn roofing with exposed screws.

All but one of the companies fabricate the roofing onsite. They order rolls of flat steel in the color and texture that you choose and then bend it into the profile of the standing-seam roof -- just like running off continuous gutters -- same machine just with wider capacity. We have a screwy roof with several dormers and too many valleys so this certainly made sense. No way could this be a DIY project using this approach.

We got a really good price for metal, but ended up going with a pro-grade shingle. Our roofline is just so cut up that I thought shingles would look better.

Oh . . . and about the metal that looks like shingles or tiles . . . That stuff is aluminum and has a dense foam backing that goes on under it. (Not separately -- each "shingle" is made with this foam backing attached to it so they're installed as one unit.) It's the foam backing that gives it enough strength that you can walk on it. Without that it would just cave in / dent under your weight. It was about twice the cost of regular standing-seam metal.

 

[CliffordK]

After quite a bit of scouring, I found a used roofing machine on Craigslist. Shipped to me down from Alaska.

So next summer will be about learning to make roofing.

This is an older type of crimped standing seam. While there may be some options to change patterns, it may well be orphaned by the manufacturer.

Most of the newer roofing is a snap lock standing seam. I'd imagine that my crimped standing seam will be very waterproof, but would be a bear to repair if that is ever needed.