EPDM - Transition to shingles & transition to gutter question


This is a followup question to an earlier EPDM question I asked about an improperly installed EPDM flat, small, second story deck at my son’s house. Great tips and advice and the roofer is tearing out and reinstalling that part of the project tomorrow.

A second area of EPDM he had installed two weeks ago is over a bedroom. The roof is very low slope, but not totally flat. The roofer also used EPDM on that roof. The EPDM transitions to shingles with a 7/12 roof pitch.

I have attached a photo showing the transition point of that roof. I’d be interested in comments about how this transition was done. My research tells me this may not be done correctly. Sorry, it is the best photo I have.

Also, the second photo shows how the EPDM was rolled down the fascia and terminal bar screwed into the fascia. Is this the appropriate way to finish this edge detail?

Thanks again. I am just trying to see that my son gets a good, solid, weather tight roof over his head and doesn’t run in to more issues with the new roof than he had with the old, which, I might add, was not leaking but had reached the end of it’s useful life.


The first pic I would need to see up closer to say for sure but from what I can tell I see no red flags with it. The second picture is fine. There are several ways to finish epdm on fascia and this way is the best as for function (however worst when it comes to looks).


Thanks. Yes, the terminal bar is ugly. Should it have been installed so that some rubber was overhung down over the back edge of the gutter?

As for the first photo: seems to me that both Firestone and Carlisle installation specs say that the shingles should be higher up on the roof plane and not brought down so low as to virtually touch the flat portion.


Also, should the terminal bar be caulked at the screw hole


There isn’t any problem with the shingles going down almost the whole way to the flat section, I do it that way myself depending on the situation. No, the screws don’t need to be caulked. In a perfect world yes the rubber should have extended into the gutter but this is a very minor issue. If (and only if) water ends up dripping behind the gutter a piece of aluminium can easily be slid beneath the epdm to divert the water over the gutter. Super simple fix and doesn’t justify any major redo.


Thanks IslandRoofing!


In my opinion, shingles SHOULD be above transition at least one or two courses. Nail holes only 5" above a very low sloped roof could cause issues with capillary action in a very heavy rain.

In this case, you are probably in the clear since you have such a severe angle change from your steep roof. If your shingle roof was a 4/12, I would be much more concerned.

Term bar is probably fine for residential use. Really the term bar/water block into gutter allows for the best water flow into the gutter. If there was cover tape along the perimeter, you would most likely see some ponding. Plenty of architects specify this kind of detail.

But, non-reinforced EPDM (which you appear to have) should not be directly term-barred. The fasteners should penetrate through something with reinforcement to prevent tearing. (Poke a hole in a rubber glove and watch how it grows when tension is applied). A reinforced strip (Russ/RPF) would probably help at this location. That would require the cover tape mentioned above though^.

I think you are probably fine, but I would watch these things over time. If you notice the rubber starting to tear at the term bar, it could spread above the angle change quickly.


Great information. Thanks!


Island is correct on both accounts- edge detail is ugly as sin and will definitely cost you in resail value down the line, but it’s acceptable. The only thing you really want to be sure of is that a heavy bead of butyl / waterblock mastic is between the membrane and the substrate- you should be able to feel it right above the term bar, or possibly see a little oozing out around the fasteners.


There’s no mastick behind this terminal bar. None.


None would be a problem, especially living in the Midwest.
See he attached detail- this uses drain bar (taller version of termination bar) the water block is what acts as the seal between the roof and the house! Premature edge rot and failure without it…


They put some mastick between the terminal bar and the EPDM on the edges where the EPDM rolled up the walls. But as far as I can tell on the edge where the terminal bar is screwed through the shingles there is no mastick at all, in either location.


That’s a good catch TJ. I hardly ever use the t-detail when I do EPDM but when I did I never realized it was spec’d that you are supposed to use mastic behind it. While I don’t think it is a leak hazard I will be doing that in the future from now on.