EPDM to composition in CO Monsoon

[SVO]

Hey all,

Some have likely seen the news coming out of Boulder, CO area. I've got a house that had the top 6' simply lopped off of the design to meet height limits. Dead flat EPDM sheet over OSB was used to seal the cut. Transition to asphalt shingle at approx. 30 degree slope. The transition seam (maybe 50 linear feet worth) is obviously a major leak source, especially under current conditions. House is a decade old.

So, my question is how, if at all, is the way to build that EPDM to composition transition right? Checked out some of the documentation at Firestone site but could not find anything applicable.

Thanks for any guidance,

JD

[Marc]

How about a short parapet, say 6 inches, to separate the two? Flashing, counter-flashing and a cap. Add a drain within the flat roof if needed. Might help with curb appeal.

Marc

[SVO]

Thanks for the idea. Seems like that would work but would be a pretty expensive solution, no? Flat roof would need to slope to the drain inlet. If the house needed an entirely new roof that might be the way to go, but it doesn't. It needs to not leak at the transition. Looks good as-is too.

[Tom Raymond]

Base sheet. It's a lot more forgiving with a little underlayment.

[Rocon]

Here is an example of what worked OK but i would not recommend in your climate. You could use sketch 1 as a starting point.

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[John Kogel]

What we do here in the rainy NW is torch-on roof membrane (modified bitumen) brought down over the edge and sealed to the shingle layer. No parapets or curbs to stop the runoff, just a good tight seal.

EPDM is not often used for flat roofing here, maybe because it is difficult to seal properly, being flexible. Roofers can't seem to learn how to work with it. Even if the edges are sealed down, it will leak around the plumbing vents.