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bart_nathan

Corrugated metal roof

5 years ago

We are considering having a corrugated metal roof installed to replace our shingle roof. Standing seam is out of the question due to price. Usually, when I look online, asphalt is compared to generic metal roofs, or standing seam is compared to corrugated. No where can I find anything about corrugated vs shingles. I'd prefer answers from those with experience in corrugated roofing, rathaer than re-quoting things found online. Some questions then:

  1. Corrugated,m because of the number of attachment points, supposedly has a chance to leak more than standing seam. How about compared to asphalt shingles. A lot of attachment points there. If installed correctly, do corrugated roofs really have a high risk of leaking?
  2. From what I've read, the attachment bolts on corrugated roofs need to be tightened routinely. Have people with this type of roof or installers found this to be true?
  3. Standing seam can have a layer of air beneath the metal, apparently not so with corrugated. How much of a problem is this? Asphalt does not have an air layer either. How does corrugated compare to asphalt shingles in this regard?

Thanks in advance.


Bart

Comments (14)

  • 5 years ago

    I owned a home where the previous owner installed a standing seam metal roof, the type that was fastened with screws. What a nightmare. If you can't afford the J or G clamp style of metal roofing attachment, don't do it.

    The roof was a 50 year roof. Every ten years the old screws have to be removed and a newer, larger screw has to be put in the hole. Our roof required 3, 500 old screws be removed and 3, 500 new larger screws be installed. You can do this four times and the roof is done.

    As the roof heats in the sun and contracts in the shade, the screws eventually begin to work their way out because of expansion and contraction. There is no way to avoid this cycle. Eventually, you will have a leak and will need to do the tune up. You will need to tune up the roof every 10 years or so. Finding someone who can do this type of work, not fall off the roof and not miss a hole is not easy. The cost of paying this roofer is very high, too. This phenomenon of expansion and contraction makes for an expensive mistake.

    I would advise against this. There is a reason why you see this type of roof on farm buildings, sheds and barns. It doesn't belong on a house.


  • 5 years ago
    last modified: 5 years ago

    This ^^^^ and a corrugated roof is typically an exposed fastener system.

  • PRO
    5 years ago

    What is a "corrugated metal roof"? Do you have a picture or link?


    You might consider a concealed fastener, snap lock roof. It's similar to a standing seam.


    One example: https://www.abcmetalroofing.com/Residential/SL-16-/


    I've installed this type of roof, and recommend it to my customers as an upgrade to an exposed fastener install.

  • PRO
    5 years ago

    When I think of "Corrugated metal roof" I think of hurricane damage.

  • 5 years ago

    From first hand knowledge, many who go to a metal roof from asphalt shingles leave the existing asphalt roofing in place (as long as it's not many layers thick), attach wood purlins parallel to the roof ridge at 24" on center, and install exposed fastener metal roofing over that. The metal roofing weight is very small and, at least here in snow country, snow doesn't stay on it for long.

  • 5 years ago

    PPF's roof is the right answer. The cost will vary dramatically on that depending on the complexity of your roofline because all the special trimming out that is required to make this look good.


    Do not use exposed fasteners.

  • PRO
    5 years ago

    I know the hassle of which you speak. Many older homes in the ski resort town I used to live in had the old school style of metal roofing to which you refer. I used to have 2 clients that would specifically ask me to inspect & repair any washed/pulled/destroyed screws every summer on their entire roofs. Corrugated S channel roofs as mentioned by other commenters above have many EXPOSED attachment points, hence their weakness. The rubber washers on all the exposed screws wear out in high UV and heavy snow load areas (valleys) first. As far as an air gap underneath metal, this can vary highly dependant on a multitude of factors, including material profile, underlays, attachment methods etc.

    I have a metal standing seam roof on my house, and there are no screws showing, expect the ridge caps & eaves. This is the way to go IMO, but if you're on a budget & can't afford the standing seam versions, I would stay away from corrugated metal roofing entirely, & stay with perhaps an architectural asphalt shingle. Good luck :)

  • 5 years ago
    last modified: 5 years ago

    OP here. A couple of clarifications here. The metal is Kynar 500 dipped/painted. Comes with a 30 year fade warranty. Likely we will get panels with 12" OC ridges (see picture). I also added some pictures of potential similar installations. I know standing seam is better. I

    you get what you pay for. What I am wondering is if it is worth it to get an exposed fastener roof, rather than asphalt shingles?



  • 5 years ago

    "What I am wondering is if it is worth it to get an exposed fastener roof, rather than asphalt shingles?"


    Absolutely not, take the asphalt all day. It will be maintenance free. With the exposed fasteners you will be replacing them every few years.

  • PRO
    5 years ago

    Bart- exposed fasteners are exposed fasteners whether the roof is corrugated or ridged like your sample. Only waterproof until the rubber gasket fails or the screw pulls out as everyone has said. Asphalt is a better investment. Thirty year paint warranty doesn’t warranty the screws.

  • 5 years ago

    We have that roofing on our barn. Going on 4 years and the screws so signs of leaking. Don't really care since it's not closed in to begin with. Another thing to be careful of is not denting it while installing. My husband was very careful while screwing it all down and it looks nice.

    Our neighbors put in on the wrap around porch portion of their home and it looks like someone tapped danced all over it. How thy managed it dent it that badly we don't understand.

  • 5 years ago

    The simple answer is No.


    Bad decision. Bad material. Bad result.

  • PRO
    5 years ago

    Why set yourself up for constant maintenance IMO get the best metal roof or go a good quality asphalt shingle .

  • 5 years ago

    If the example you show of roof lines is anything like final design, I wouldn't put a metal roof on it anyway. The break in slope and the dormers will require detailing and craftsmanship to not leak. And will be expensive.