I have this rubber membrane roof where it seems like the insulation below has warped or let loose and is causing these “lumps.” From my research, it seems like this is normally caused by either improper insulation fastening, or by the insulation being wet (either when installed, or subjected to moisture later).
Can anyone add a little more “color” to this situation for me?
I cant, but what a mess…
The wetness probably makes it look a little bit worse than it actually was. But nonetheless, I could push the underlying insulation down a bit with my feet. So it was definitely loose.
Not sure about the big lumps/raised areas. But it looks like there’s a lot of smaller air pockets, at least from here.
I suppose some of that is related to the foam insulation stretching the membrane when it bows upwards. Then the insulation and/or membrane relaxes a bit and air comes in?
Are you sure it’s a foam backer board?
Not 100% of course as I wasn’t able to directly observe it. But I could push it down with my foot, so it was loose and it sounded like foam being "flexed "
Were you able to see the decking underneath? Curious if it was wood or steel. I’ve installed many flat roofs like that but haven’t seen one buckle and bulge that bad before.
It was wood. A few places inside had some stained ceiling tiles so I popped a few open in those areas and the plywood deck had some water stains in those areas. But, those areas all seemed dry at the time of inspection, and we’ve had quite a bit of rain lately as well as very “dewey” mornings.
I’ve also always understood bubbles like that to typically be a result of moisture, but I have never seen any that big.
I’m no expert on rubber roofs, although I’ve seen quite a few. I know some of the local commercial establishments have a contract for annual inspection of the roof by a commercial installer. You might see if the seller has such a contract.
I have seen humps before, but not to the extent of yours. As I understand, they typically are not adhered to the substrate. Sometimes 3/4 rock is added to the top, loose placed, for ballast.
Re moisture: You might consider recommending an infrared thermographer do imaging to look for evidence of moisture. There is a procedure for that.
In this case (and I know it is for your edification) it is nearly impossible to determine the cause. EPDM can be installed over a number of substrates in which the condition of the substrate can vary significantly. You will have to focus on the consequences this has on the roof covering material.
Edit: I would certainly comment on the obvious poor condition of the substrate.
Hey buddy so here in Arizona we use a lot of polyurethane spray foam roofing. They pressure wash the substrate surface before applying the new foam, if that is not dried 100%, you end up with a bunch of blisters which need to be popped and cut out and reapplied but that whole buckling looking thing at seams is really abnormal
