Shingles on less than 10 degree slope

I have a dormer roof (10 degree slope) that goes into a covered deck (6 degree slope). It’s new construction and I was fully prepared to get torch on roofing. I’m in the process of getting quotes and three roofers have told me they would shingle that roof. Does that sound right? I thought u need at least 15 degrees for shingles?!

Well, now you have 3 you can take off your list to do your roof. 14 degrees minimum and I prefer a 4 pitch, 18 degrees. You may not need torchdown but shingles are not the answer.

Who designed the roof with those sort of pitches?


Ha my husband did. :woman_facepalming:
What other option would u consider if not torchdown?

There are many factors involved. Where are you located, elevation, how much distance between eave and ridge, type of shingle. There have been three tab roofs installed on those pitches under certain conditions that worked fine, even before ice/water shield was commonly used. We have done many porch roofs in Southern Oregon over ice/water shield that have been doing great for 20 years. Malarkey shingles have tapered their shingles well for low slope roofs but I still wouldn’t use them on a 25’ run.

I just tore off a Landmark roof I put on 23 yrs ago.

A small part ( about 5 sq) of it was 3/12 that I shingled, there were a few spots were the nails were starting to rust but it was otherwise in good condition.

This has a 10/12 dumping onto it.

The roofer needs to pay extra attention to what he is doing and needs to make a bigger lap and even a shorter exposure.

I’m on the east site of Houston. So hurricane force winds are definitely possible as well as lots of rain throughout the year.
The roof is 32’ wide and 36’ from ridge to eave. The upper 20’ have the 9-10 degree slope, bottom 16’ only 6 degree. It’s a second story roof.

I’d recommend a PVC roof with a shingle pattern on it.

I’ve never heard of a PVC roof. What manufacturer makes those?

Company called IB, very good but expensive product.
I would use a torch applied roof there, I wouldn’t want to have shingles on that roof.

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Major difference bewtween 9 & 10 degrees when shingles are involved. Personally I won’t install shingles on anything less than 3/12.

In Texas where it is hot and humid I wouldn’t use full ice and water either. I would use 3 ply torch down with mechanically fastened ventilated base sheet.

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Just do an EPDM membrane roof if it’s not really visible from anywhere (they’re very commercial looking).These roofs are designed for dead flat roofs so they’re great for low slope applications. Cost is roughly the same as a torch on roof but there’s no open flame required and the expected lifespan is longer than torch on. The torch on roofs are good too, but make sure your installer shows you proof of open flame insurance because it doesn’t take much to burn your house down with the huge torches. There’s also TPO membrane which is similar to EPDM and it’s white instead of black. Basically my point is to treat that low slope roof like a flat roof and use a flat roof product. Most of them are good and durable. The downside is the installers. Make sure they’re good or they can make a real mess of even the best materials. Get references.