I owned a home in San Francisco with a flat tar/gravel roof. It had some minor ponding issues and eventually some minor leaks that I had repaired.
I'm now considering making an offer on a very nicely remodeled Eichler and I have to say that the flat roof is giving me pause. The roof is foam, is 9 years old, and has some minor ponding. It just doesn't leave me feeling very confident. And it's not clear to me that you can fix the ponding until the new roof is installed.
What are your experiences? Do they all have some ponding? Should it be a serious conscern? Can a flat roof with foam or tar/gravel successfully be installed with complete drainage? Is this just part of living with an Eichler?
since you've had 108 views and no replies, i'll jump in from a layman's POV. hopefully randy can add an xpert opinion.
from stories and a bit of experience, some ponding is normal and as long as the topcoating (the elastomeric coating over the foam) has been maintained and renewed once during that nine years, it should hold water fine. it's true, you can't really address the ponding until new roof time (which should be quite a while with a maintained foam roof), the flat part of our roof has some ponding and have never posed an issue. to be honest, i'd guess ther was ponding with tar/gravel, just a bit lass noticable with the rocks.
if it's something that's a deal-breaker, work a roof inspection into your overall house inspections. i'd be more worried about non-grounded electrical, single pane windows and/or asbestos ladden flooring than a ponding foam roof.
I have a foam roof on my Eichler and there has always been some ponding issues but none that were causing any leaks. As redneck stated if the topcoat is maintained you shouldn't have any issues. Even if the topcoat is older the nature of the closed cell foam that is used will prevent any leaks. I believe that the topcoat along with some water protection is ment to protect the foam for UV degradation and provide heat reflectivity.