TPO membrane over EPDM

I agree with Mike H. I would tear off, but if not you could adhere the insulation with a rising foam adhesive like olybond. Either 1/2" fiberboard or 1" polyiso. Then fully adhere the tpo.

You might consider gluing recovery board to the E.P.D.M.; and going over that with the T.P.O.. Years ago, we used hot tar over B.U.R. to hold the recovery board and over that installed torch grade modified. The concept is the same.

Yeah, and I was hoping he'd say why.

He said TO was not an option.

Do all you guys really consider a roof mopped to concrete to be impossible to tear off? It takes some work, but it's not that hard, and if the fiber board is wet, and since it needs a new roof, it probably is, it might come off pretty easy.

There ya go!....I didn'r even consider ballasted....Just get a structural engineer's blessing.

You can loose lay epdm with ballast on it or mechanically attached recovery board with fully adrehered tpo on it.

Why is tear-off not an option?

Then, if that's the case; A recovery board must be "glued" to the EPDM & subsequenbtly fully adhere the TPO to the board....Don't forget some venting, as well....

TBR Said: Can you glue TPO membrane directly to EPDM. If not what would be an alternative. The roof deck is concrete and has asphalt empragnated fiber board glued to it with EPDM over that. Tear off is not an option.

You CAN NOT glue TPO to a EPDM roof. Is there anyway you can provide me pics of this to give you a better solution?

Wouldn't think there would be a problem, as far as bonding TPO to the EPDM, as far as that goes....May be other issues with the overall system...A quick call to your material tech dept. will get you a definitive answer.