RE: Metal roofing

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

firefighterjake

Minister of Fire
Jul 22, 2008
19,588
Unity/Bangor, Maine
My wife's and my plan this Fall was to put in new windows on the second floor and replace some cedar shingles on the walls . . . but that changed when I was up on the roof the other day and discovered that a number of the 30-year asphalt shingles are in really rough shape (the granules falling right off just by running my hand over some of them and exposing the backing).

I'm a little perplexed as to how this has happened . . . unless 30 year shingles are in actuality only really good for that time in an ideal situation as they have been on the roof for 17 years. My only other line of thinking is that where the worse damage is located is at the point where the snow collects and sits as the roof line transitions from a steep point to the less pitched porch roof . . . OR . . . maybe it's because I insulated the knee wall void space and there are no vents in that area?

--

In any case, besides wondering about the cause of this failure . . . I am also looking for opinions on metal roofing. I am leaning towards standing seam . . . but I'm also getting a quote from the local Amish family that sells and puts up the "old" screw in style of roof.
 
Go with the standing seem, superior product all holes in it are concealed from the weather rather than exposed to it as with the corrugated product.
 
You probably have thought of this already, but there are some things to consider when it comes to metal. The snow slides right off, so you don't want to slam the front door if the roof comes down that way. It is also quite noisy in the rain. I think standing seem metal looks great, but I wouldn't be able to use my front door during heavy snow storms.
 
Very common for 30 year shingles to not last for 30 years. Sad, but I guess we have to live with it.
 
  • Like
Reactions: ScotO
If those shingles are under warranty, then call it in. I have seen shingles rated at 15 years way back last 20+ years. My parent's place has 20 year shingles that are in great shape and been on the roof 27 years now. They should last no less than the rating, usually lasting longer if taken care of.

There has been instances over the years where bad batches happened and would delaminate quickly. I would push for the warranty first. Even if they pro-rate them, you may get something to put as down payment or pay a part of the new roof.
 
I've heard about some class action lawsuits that have been or are being brought against some shingle manufacturers. Certainteed being the one I've heard the most issues with. May want to look into it.

Sent from my Galaxy Nexus using Tapatalk 2
 
I got 16 years out of my 25 year shingles - and they were about 2 years overdue to be replaced when I replaced them. I have heard lots of stories about people getting only half the rated life out of their shingles here, but have heard of no one being successful in getting any warranty compensation. I put steel on, but the kind with exposed screw heads. Snow slides off, yes, but you can get little thingies to put on the roof above the doorways under the screws that will stop or control that - I should do that in one place here.

And it is not noisy at all.

I would not put shingles on my house roof again.
 
  • Like
Reactions: ScotO
I have a metal roof on my house, the old screw in type, and the screws are the only part I have to complain about. The roof is ten years old and is in great shape, save for the few screws that have backed themselves out I had to put back in.

As far as the rain goes, you have to be upstairs in an extremely heavy rain to hear the roof. The metal sits on top of OSB so there isn't much noise that comes through unlike barns that only have the cross ties to fix the roof too. The only time that I really wish I had shingles is when I have to get up there and spray it off, I have a pretty extreme pitch and it gets real slick.

Honestly, if I were to redo my roof I'd go metal again, but assuming I don't live here for a century, I think paint will be the only thing I will need to do with it other than replacing the occasional screw.

David
 
Heat and moisture (and hail) are what kill shingles. If you have a low pitch the moisture won't run off as fast. If you have an unvented attic space that could generate some serious heat.

30 years probably best case scenario (12-12 pitch in full sun with a nicely vented attic) in my experience. If you have a lot of shade/low pitch/hot attic they will wear quicker.

As for metal, you get what you pay for. The exposed fastener isn't bad stuff, but the gaskets on the screws are your potential leaky spot. Standing seam has hidden fasteners and looks a lot nicer, but at a price.

If your roof is decked (it is because you have shingles) and your attic is insulated (it is) then noise won't be an issue at all.

Around here the Amish do a lot of metal roofs and post frame construction. They tend to be pretty reasonably priced and get the job done QUICK. They'll bring out 12 guys and be done before lunch for a residential roof job.
 
Egads . . . received two of the four or five contractors who are quoting on this job and I was rather shocked by the price. At this point while I like the standing seam we may be looking at the (I assume) cheaper conventional metal or even going back to asphalt shingles depending on what the last few quotes look like.
 
Metal and shingles should work out to be about the same. Materials cost more for metal, but labor is cheaper. Opposite for shingles.
 
Do NOT get exposed screws. They will leak. You have thousands of little holes with the screws and a cheezy little gasket that is very easy to over or undertorque based on wood density and operator skill and cause leaks. Standing seam is much more dependable.

I have shingles now and have had more problems with installation errors than with the shingles failing. Seems there are many methods used to shingle a roof and the details are often screwed up. Little things like roofing around a pipe penetration can easily be screwed up but considered "right" by the installer.

Basic rules, Never expose nails except at the last shingle on top. No cement.
 
I 2nd what Highbeam says about the exposed screws. Those who install these types of roofs will tell you they don't leak. I think they're wrong. I have this type of roof on a large shed and would never use it on my house.

I'm assuming that a metal roof is better for fire prevention from falling embers but I'm sure you would know better than me on that. Where I live near a national forest, that's a big plus.

Summer attic temps may decrease with a metal roof also. There used to be associated energy star tax credits. That may not be an issue for you in Maine though.
 
Most real commerical roofers in Northern NH and vermont recommend that you strip the old roof down to underlayment and then install WR Grace ice and water shield (or equivalent) on top of the deck prior to installing either standing seam or exposed screw roofs. Most of them learned that if a metal roof does leak its almost impossible to find and fix the leak. With ice and water shield underneath, all the metal has to do is keep the UV off the underlayment. If you use Galvalume and are away from the coast, its the closest thing to a 100 year roof. I would not recommend the low budget way of installing some strapping horizontal on top of the old roof and installing the new roof on top, unless you are planning to sell the house soon.

I see quite few contractors that advertise standing seam but usually convince the owner to subsitute screw on type material. Its a lot cheaper and they can tack on a better profit than with standing seam that requires specialized tooling.

If you have a roof with lots of gables or stacks be aware that the costs go up quite a bit for metal and the potential for leakage also goes up significantly. Many builders install "crickets" on any roof penetration as sliding snow can get a lot of speed behind it and rip a standard roof boot and I have seen metal chimneys bent over by a snow slide. Roof hooks to keep the snow from sliding work pretty well but make sure you have a roof that can take the load as many older roofs are designed to shed or melt snow quite quickly. Snow hooks can be a PITA when you need to rake a roof off due to high snow load, once the snow freezes into the hooks it isnt coming down. These days with super tight attics and "cold roof" concepts, snow may hang on for quite awhile and a standard Maine roof is 40 PSFmax which is about 4 feet of snow, add in a rain storm and its time to rake.

By the way many commercial buildings with asphalt shingles specify ice and water shield underneath. Its cheap insurance. Even if there is a windstorm, ice and water shield once installed will not rip off in high winds, the whole roof will lift off before the stuff fails. I did my entire south facing roof with it under my shingles as I was planning to add on solar hot water panels later which required a few roof penetrations. It also menat that will I was putting the shingles down I didnt need to worry about it raining.
 
Even if you apply the ice shield, won't all the screws punch thousands of holes right through it? I've seen water run down a screw used to retain a rubber fart fan vent and into the attic.
 
"Real Commercial roofers" typically are not doing much residential roofing. And doubtful they are installing nail or screw through systems. No architect would ever write that crap up on a commercial building. On residential, sure, not on commercial. I would not even suggest it on residential. Barn or shed maybe, not my house no thanks.

Standing seam, now that is a different story. If properly flashed and installed, it won't leak regardless of penetrations, valleys etc. Problem is lack of truly skilled roofers in installing such roofs, and others rushing to slap the roof on. All comes down to the quality of the install, and the experience of qualified, knowledgeable mechanics.

Standing seam comes in a few designs. One design is such that one panel side edge overlaps and snap locks onto the last panel. Works well, and installs easy.
Next is the batten style standing seam. Where the panels are merely "U" shaped and a batten & mounting clamp system is used to both hold the panels down & snap the battens on to. Not the best, but works as long as it is fastened to a solid substrate or lath. Not recommended for over top of rigid insulation, or any insulation for that matter. Had an architect spec it over Iso board, and the clamps would not get tight enough to hold the clamp tightly down against the Iso board. Results where the panels sliding down, as well as the battens. Don't care for that system myself.

Old school standing seam is usually Terne coat metal, usually tin. The panels are each hand formed, and each one is formed to the next by hand tools, hammering & a couple foot actuated benders. True "tin knocking".
Every seam, and bend is soldered. I was lucky enough to be taught this old world method with the true old school tools and techniques. Did an historical church back in the 90's. Drove by it the other day, and it is still intact and in great shape. Sadly they did not keep up with the paint, and it is starting to peel off. With proper care & painting, these roofs last longer than the average man and more. Not sure how many still install these roof this way. Was a very fun and crafted roof to fab & install.

If you have the extra bucks, skip the screw through "barn" metal roofing and get a the snap lock. Can be had in aluminum or steel. Usually has a 50 year Kynar finish. Aluminum of course lasting longer, but also more expensive. Easier to work with also.

Screws with neoprene washers fail. And it can be a while until you notice the washers are rotted or gone, and the damage could be done already. That system is only as good, stays tight only as long as those washers last. Replacing several hundred or thousand screws is not fun.

Choose wisely, not just cheaply.
 
We've had the screw on system that came with the house. It's about 7 years and so far, so good, knock on wood. Hoping for the best. Might take a look at some of the washers I can see easy on the porch.
 
I put a metal roof on my garage about 10 years ago. Galvalume, standing seam with exposed screws through the ribs. Nailed 1/2 wood purlins right over the original shingles (which were leaking in several places), the metal roof goes over that, with the screws going through the purlins. I've had no trouble with it, and am planning to do the same for my house next month.

It worked out that buying the materials for the metal roof and installing it myself cost about the same as hiring a roofer to put shingles on. It's quick... I did the 2 car garage entirely by myself in two [long] days.

Most people I talk to consider the noise of rain on a metal roof to be a desirable feature, not a problem.
 
Update . . .

I think I am shying away from the screw down type roof that the local Amish sell . . . for many of the reasons mentioned here.

I did find this product on line though . . . it doesn't use clips, but it has a hidden fastener system with apparently some slots for allowing some thermal expansion of the product.

Opinions?

http://www.bestbuymetals.com/standing-seam-metal-roofing.html

http://www.bestbuymetals.com/pdf/standing-seam-installation-guide.pdf

http://www.bestbuymetals.com/pdf/standing-seam-brochure.pdf

http://www.bestbuymetals.com/image-ii-standing-seam-install-video.html
 
A friend of ours just installed the screw type metal roof. Aside from the obvious (thousands of holes in your roof), the very next thing I noticed was that it was open on the edge. I can't imagine that bees don't find that beyond tempting.

We plan to eventually replace our shingle roof with a standing seam roof, although I'm not sure who we'll have do it, since #1, metal roofs are not common here to begin with and #2, the ones I've seen are all the screw fastener types. If we didn't have a valley, we'd try it ourselves. We'll probably see if wherever we find that sells it can give us a few names, then check them out. I'm afraid to even think of what it'll cost though, lol.
 
A friend of ours just installed the screw type metal roof. Aside from the obvious (thousands of holes in your roof), the very next thing I noticed was that it was open on the edge. I can't imagine that bees don't find that beyond tempting.

Shouldn't be open anywhere... there should be a rake edge that seals the gable ends, and the manufacturer sells a closure strip to seal it on the peak and eave ends.
 
A couple of years ago we had a serious weather event and had to replace our roof. I say weather event because it was hurricane force straight line winds with quarter to golf ball sized hail. NWS stated that since there was no rotation recorded that it wasn't a tornado.

Anyhow, we looked into several roofing scenarios for our replacement and my first choice was a standing seam galvalume roof for multiple reasons.

1) Steel is recyclable and has recycled content.
2) Limited lifetime warranty
3) High emissivity, which is the measure of how much solar heat it reflects, helping reduce heat build up in attic resulting in lower cooling load during summer.
4) Zero maintenance.
5) I like the galvalume aesthetic.

Unfortunately, I too got the sticker shock that you are seeing of the system being double the cost of a 50 year architectural asphalt composition shingle. Since this was an insurance claim, and I was (and still am) unemployed, we had to chose the shingle roof.

As others have mentioned, I would steer clear of exposed fasteners that penetrate the metal panels and roof sheathing. Save this for less sensitive structures like outbuildings.

Updates to the building codes have changed roofing procedures recently, and depending upon your Authority Having Jurisdiction (AHJ = building department) you will most likely have to do a complete tear off. If you are really planning to put down a metal roof, or even a high end shingle, I would advise against roofing over existing. I also would recommend a complete inspection of your roof sheathing, and then installing a complete layer of ice & water like has been recommended. Yes it costs more than roofing paper, but it performs many times better. It also is supposed to be self sealing around whatever nail penetrations are necessary, while paper is not.

Cheers and good luck with the new roof.
 
Metal roofs aren't common in western NY? With all that snow?

I'm no roofing expert, but it seems to me that the Image ii system depends on the interlocking action and might use less screws to hold things down to the roof. You're depending on the interlocking action. I mean, I sure it's been tested and all, and it would be nice to not see all those screws.
 
T
Update . . .

I think I am shying away from the screw down type roof that the local Amish sell . . . for many of the reasons mentioned here.

I did find this product on line though . . . it doesn't use clips, but it has a hidden fastener system with apparently some slots for allowing some thermal expansion of the product.

Opinions?

http://www.bestbuymetals.com/standing-seam-metal-roofing.html

http://www.bestbuymetals.com/pdf/standing-seam-installation-guide.pdf

http://www.bestbuymetals.com/pdf/standing-seam-brochure.pdf

http://www.bestbuymetals.com/image-ii-standing-seam-install-video.html
Yes, that is the type your looking for to avoid exposed fasteners. Not sure of this specific brand, but the slots do allow for expansion(as long as you don't crank the screws too tight). Make sure it has a warranted good finish like Kynar or similar to.
 
Status
Not open for further replies.