Hi, I've got a bay window with a torched on mineral felt flat roof with a gully against the main wall of the house again formed with felt. The felt in the gully is in poor condition and I think it will be difficult to remove. I'm thinking of sticking EDPM rubber over the felt as it's more flexible than mineral felt. I've got some spare EDPM pond liner and assume its the same as what's used in roofing. My question is what adhesive should I use to fix the EDPM to the existing felt. Thanks guys.