Anodized aluminum vs. some other metal roof option
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| Posted in Energy Efficiency and Durability on
We have a summer cabin in Maine with a 60 year old metal roof that needs to be replaced. The pitch of the roof is unfortunately so shallow that the roof must be shoveled throughout the winter. The cabin is not insulated.
We like the idea of using anodized aluminum for the roof but are afraid it might not be able to stand up to all the shoveling. If anodized aluminum is not a good choice what would you recommend?
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Replies
Why does it need to be replaced? What killed it? A good metal roof can last for a century or more. Whatever you replace it with, it might make sense to determine the problem first so you don't inadvertently replicate it, necessitating another costly roof replacement 60 years hence.
If you must replace it can you increase the pitch of the roof?
The cabin sits by a lake and Maine Lake code prevents us from increasing the pitch of the roof (which is extremely rusty at this point) because it would increase the volume of the cabin past the allowed amount. We are stuck with the pitch that we have.
Shoveling aluminum with a steel or steel edge shovel would scratch off the anodizing pretty soon. That is okay if you are OK with the way that looks. But the life might still be limited. Shoveling with a plastic shovel should help a lot, but I would still think the anodizing would eventually wear off.
What about reinforcing it structally so that shoveling is not needed?
Or increasing the pitch by raising it on one side but lowering it on the other.
Perhaps its worth going down to the code office and having a chat with someone there, nothing may come of it but maybe you might get someone willing to give a variance or have an alternative idea?
Or she could put on a thick anodized or Kynar finished roof and get another 60 years out of it without messing around with the rest of the cabin.
Thank you for your help. I realize that changing the pitch of the roof would solve the shoveling problem. But please believe me, I have spent quite a number of years trying to get a variance. We have already used up our "expansion quota" and the shape of the roof can not be changed.
I will check into a thick anodized or Kynar finish.
Stephanie,
Both anodized roofing and that using galvalum based panels (which are then coated with a Kynar paint) are to some degree self-healing. Incidental nicks and scratches don't affect the material underneath. With a bit of care in how you shovel, which I'm sure you have more than enough experience with, both types will last a long time. The reason I mentioned a thick anodized roof is that anodizing is done to various standards, from almost useless to quite robust.
Thank you Malcolm. That's really helpful. I did look up "hardcoat" anodized aluminum and it looks like just the thing. Thank you again.
I bet you really appreciate how your local planning and code department helps you build high-quality structures. All those tax dollars put to such good use!