My patio roof has about a 7 degree slope (1.5:12) and was previously covered with corrugated polycarbonate panels. They had become quite brittle and cracked in several places and were mildew stained so I took them off and have cleaned and painted the underlying structure. Now I'm trying to decide on new roofing material and struggling to identify any options...

I had first though about just putting up plywood and shingles but the slope seems too low for that. Membrane roofing would work, but it's not the most attractive option a for backyard patio. There are some metal roof panel options I can find at the box stores, but none are rated for a slope this low, I'm guessing because of the exposed fasteners. Metal options that can handle a slope this low do not seem to be readily available at the consumer level.

At this point the only thing I can really find that is suitable are twinwall polycarbonate panels which will work, but I'm skeptical of how long they will hold up.

Are there any options I'm missing? I've tried calling roofers to see about a proper standing seam metal roof but none of them are interested in a job this small.

  • 1
    Metal roofing is indeed widely available, but not for a low slope roof. The only suitable metal roofing I have found that is approved for a low slope roof is a standing seam metal roof with onsite seam sealing which is not a very DIY friendly option.
    – Chad
    Jul 28, 2023 at 15:33

2 Answers 2


I did a similar project on my old house in 2010, with a 12:1 sloped patio roof. I did plywood deck, with tar paper, and nailed a rolled granular roofing material on top. I may have sealed the overlaps with a tarry goop of some sort made by Henry. The house was sold in 2021, and I'd say it was about still about 80% good. Don't forget your drip edge.

  • I'm guessing you meant 1:12. Slope is indicated as "rise over run".
    – isherwood
    Jul 26, 2023 at 14:15
  • @isherwood depends on your background, I guess. I'm in the highway design business and for embankment slopes most state DOTs use run over rise. Although FHWA does do the opposite.
    – Huesmann
    Jul 27, 2023 at 12:16
  • Let me clarify: roof slope is rise over run. Almost universally. :)
    – isherwood
    Jul 27, 2023 at 13:18

Investigate "peel and stick rolled roofing". One of the big box stores has it specifically for low slope roofs.

I used that type of roofing on a low slope roof over my lanai. It was good for at least a decade.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.