Replace traditional shingled roof with metal roof? Experiences?

[toppop52]

Eddie, I see some of your points. I'm asking because my house is 2 years old and we're thinking seriously of installing metal within the next couple of years. My roof is perfect now but we want metal and we want to do it before we get too old to see it!

 

[Gem99ultra]

I agree with predrilling. I used to do pre engineered metal buildings, and if the screws don't line up it really looks bad.

I'm considering using Rib-12 panels when I add two bed rooms to my double wide next year. Shingles have gotten really expensive, and Rib panels can be had for less than $2/Lf for a 3 ft wide panel. I have all the screws from an 8800 sq trailer shop I did years ago (as superintendent; not my own) and that is a major cost saver. My plain is 7/16" OSB, 30# felt, and metal. I don't thick I will use the 1.5" foam under metal as it's just too much money. But back to point: that's roughly $66 per square; (unless my math is bad), you can't get 3 tab 20 year shingles for that price... Now that is 29 gauge metal of coarse; and yes, I would prefer 26 gauge, but on top of OSB instead of purlions I don't see the need (might change mind based on finances when I start).

We just had the roof over the 'sewing room' replaced. It had 10 year old metal roof and leaked like a sieve. That metal WILL rust out if there is an area that doesn't drain. It had been built on a 2/12 slope - not nearly steep enough. We had another decking built over that on a 4/12 slope to match other parts of the house. In addition, we had 15# felt laid with 3/8" foam for sound insulation - which you will find is absolutely needed, R-30 insulation over that, then radiant barrier 7/16" OSB for decking. We wanted 26 ga but were only able to get 29 ga in the 35' lengths. Metal roofers may claim a 40 or 50 year life, but I'm not believing it. Perhaps a 15-20 year life is more reasonable.

 

[texasjohn]

When building about 30 years ago, I went with metal roof hoping to be done with roofing forever. Nope. Installer put screws in the valley where the water runs rather than on top of the ridges. This was cheaper/shorter screws, but allows leak if ANY problem happens with the screw. Yes, screws had the grommet that is supposed to prevent leaks. In Texas sun, screws have backed out, pulled away from the metal causing leaks. I like the idea of metal, but didn't work at all well for me. I've been up on roof every few years repairing leaks.

On a trip to central america, in a rain forest, I observed metal roofs everywhere. they put the screws ON TOP of the ridges...that's the way they all were. Makes sense to me...wish my installer had done it that way.

I've posted my experience previously on TBN and gotten lots of "it shouldn't be doing that" comments and "that's the way the manufacturers say to do it" and "the screws and grommets will prevent leaks"....well, the way I look at it is that a screw on top of a ridge, even if it were to back out a tad, would only leak a smigen if a drop falls right on it, then runs off into the valley. A screw imperfection, anywhere in the valley will ALWAYS leak because water runs right down to it the entire time it is raining. Also, My experience is counter to most other people's comments...but then I have more years experience than most.

So, your experience may vary...hope it is a good one. roofing seems to be a problem, always. Post below is first I have seen admitting an experience similar to mine.

Yup, I belong to a club that has a clubhouse with a metal roof that is now about 10 years old. The grommets on the screws that hold the metal down are all deteriorated from the sun and the roof is leaking. It's looking like a pretty big job to replace all the screw/grommet combinations.

 

[toppop52]

Texasjohn, all the old barns in northeastern NC were nailed through the peaks, not the valley's, with leaded heads, worked like a charm.

 

[EddieWalker]

Pros and cons to both methods of attaching the metal. If the gaskets fail, then attaching the screws in the valley will seem like a bad idea. The advantage to attaching them to the valley is you end up with a solid mount. No movement in the metal. Especially if 3 screws are used for each purlin and the purlins are spaced fairly close together. I like four feet for mine, but I've read that you can double that and be fine. I also like my purlins on the flat, not the edge, but I know a lot of barns are built with trusses spaced out too far apart for purlins on the flat, so you have to have them on the edge. The biggest negative to attaching the metal through the ridges is that you cannot get them too tight or they spread the metal out. It's a fine line between tight enough and not tight enough. Then there is the concern of movement of the metal itself. With movement comes failure. How long and to what extent will depend on the amount of movement. I've read where some manufactures say they want their roofs attached through the ridges, where others want it done in the valley. You just have to weigh the pros and cons and do the best job possible. I attach in the valley with the best screws available, which I feel come from Muellers.

If screws are the problem, going with a standing seam metal roof will eliminate them. The fasteners are covered up by the next piece of metal as it's installed. It's more money and since each panel is just a foot wide, it takes more time. You also have to have decking and paper under it, so that requires more work and materials. This is how most commercial buildings, like banks and such go when they use metal roofs. I think the cost scares away most home owners.

Eddie

 

[toppop52]

We use slide down the barn roof on the lean to side and jump off about 5' from the ground, if you got one of those nail heads it was Katie barred the door for your dungarees!

 

[buckeyefarmer]

I would not want screw down metal on a house, only standing seam.

 

[Pirate]

I would not want screw down metal on a house, only standing seam.

Me too, which made it too expensive to do so I used traditional shingles instead.

 

[leveled]

I have been doing roofing for years. Just use GAF asphalt and use a certified installer and get the system plus warranty and be done with it. If you do metal use standing seam metal only.

 

[rtimgray]

I lover screw-down metal roofing for barns, shops, outbuildings, etc. where a little leak every now and then will be of no great consequence. I know that everytime I've been working in my shop or barn from morning until afternoon I can hear the expansion/contraction of the metal as the sun warms it (squeaks/pops/etc.). Everytime this happens, those gaskets get a little looser. It's been built 10 years or more, and it might have just a couple of dripping leaks, nothing to worry about in the shop - but I don't want it in my house, that's for sure.

I've helped my father in law replace all the screws on his roof - he had metal screw-down roofing installed my laying it directly over the old shingles - no purlins, no tear off, no nothing. Most of the screws we removed were rusted/rotted out and we had to remove one small piece of metal and it was rusted underneath.

I think a lot of folks like the metal for the looks, and a lot like it for the cost, because they feel they can skip the tear-off of an old roof. My opinion on roofing is that if the roof is in bad enough shape that it needs to be replaced, it needs to be removed. I hate doing roof tear-off too, but as others have said, the first step in a good roofing system is proper preparation, no matter what type of roof you're installing.

If I were to install a metal roof on a residence, it would be standing seam, but I prefer the looks of asphalt shingles. Additionally, I've only had one small portion of shingles that has ever blown up, and that was during a hurricane-force wind event (and we don't get those often in KY).

Whatever you choose, good luck and take care.