Low slope roofing question


Hi everyone, This is my first post here. :slight_smile:

We’re working with an architect to build a new 2-story house in Seattle area. The house is near several pine trees and we expect lots of pine needles. We are doing a hip roof and I asked the architect to not go below 3:12 roof in slope so we get some help from the slope. We were planning to do composite shingles.

The architect recently told us that with the heights we want, we cannot have 3:12 and we should go to 2:12. We don’t want to do shingles on 2:12. Our options are to do membrane (PVC or TPO). The architect claims that with 2:12 if we do PVC or TPO it will look ugly (even if it’s black). She’s recommending going to 1:12 so the the roof is hidden and then do PVC or TPO.

I have three questions for you guys:

1- Would PVC on a 2:12 roof look strange/ugly? I cannot find clear pictures and certainly haven’t seen a lot of houses like that.

2- With a 2:12 (or even 1:12), can we have gutter or should we use scuppers?

3- Are signing up for a world of pain with low pitch roof considering the pine needles? Would 1:12 be a lot worse than 2:12 in that sense?

Thanks in advance.


Depending on your budget there are some very good PVC options for your situation.

This company deals with residential.


IPersonally I would go with 3 ply modified bitman, granular cap sheet will look better than pvc or tpo.


Any type of PVC, TPO, EPDM is going to look odd on that pitch. These are great products and if installed to a good building standard, they will last 40yrs without any issues. They also will withstand some foot traffic to blow off the pine needles. Have you looked at a good Sheet, style metal roof? I would look at a metal option before the others. Just my opinion.


Another thing to consider when putting a slippery surface low slope product in a sloped roof is snow retention. The greater the pitch the Higher the risk of the snow load breaking loose and doing major damage.

One of the churches we work on has a 2600sq ft section 2/12 30’ above a playground that some architect decided to put epdm on. After taking the custom box gutter off the building more than once and having to cordon the area off anytime it snowed we replaced the roof with granular and snow fence.


Why not a standing seam metal roof thatll outlast anything not slate? Some are rated to 2:12.


Our latest thinking is to a shed roof (sloped to one side) with a pitch of 1:12 to 2:12 and have rain gutter on one end. The architect says this will match the style of the house better (more modern house).

What do you guys think of this type of roof in terms of maintenance (given that we have pine needles) and rain water issues?


I’m with Mia…standing seam. Shed roofs work fine…its all about product choice and installation applied to project.


I would also want a ice and water shield approved for metal roofing. The combination of the 2 will last the avg homeowners lifetime. Also easy to clean without damage.


I would also go for standing seam, traditional double mechanical locked, no new fangled junk. Good ice and water as underlayment, layor of rosin paper or synthetic felt to allow for expansion and contraction, then quality metal. Also would recommend snow guards or snow fence to protect people, property, and gutter.