epdm advice

I just recently did my first edpm job, a small little L-shaped roof with poor drainage. All went well, but I was disappointed that at the point of the folds, there was a 2-3" strip with spots of poor adhesion. I know there was plenty of glue on both sides there. Any tips on how to avoid this in the future?

I don't do a lot of EPDM work either-so i will bow to the greater expertise of those that do-

but locally we have at least 2 different types of water based adhesive . One of them is, I think from Mulehide-it smells like elmers school glue, it's white- you can just roll it onto the substrate and then flop the rubber over onto it and broom the rubber down while the glue is wet.- It's pretty forgiving-quite a bit of fudge factor for one man to get the sheet positioned correctly- but you can get some bubbling if the sun hits the sheet and the rubber gets real hot- you can also get a slight diagonal wrinkle if the sun casts a diagonal shadow across the rubber from the corner of the building

the other type-from firestone-works more like a contact cement-coat both surfaces-let them dry-flop the sheet-slightly less initial grap so you have very minor re-positioning ability-broom it in

the first type can be a problem at the FACTORY FOLD area-where a 20x50 ft. sheet is folded in half at the factory to make a 10 ft. roll-there is a semi permanent crease their that the wet glue installation method doesn't have enough grab to flatten out

the second type of glue seems to handle it OK though if you broom it down flat or roll it down well initially.

best wishes, stephen

I do not believe you are supposed to coat both surfaces with water based --- The yellow stuff is contact cement -- the white water based is glue and you can and are supposed to lay the rubber in it while it is wet then broom it you really cant use too much of it. It will take 8 -12 hrs before the water base fully cures so if that area was not perfectly flat it will cure with the rubber away from the surface -- if you are going to use the water base lay a piece of 1x6 or some plywood over any areas that are not perfectly flat.

Thanks for the responses. I did coat both surfaces, althugh it was water-based. I think Vaa nailed my problem when he mentioned too much adhesive. I rolled it on, then brushed more on at the fold just to make sure.

or if you used the water based stuff it is kinda crap

Just to make sure since it is your first -- I normally lay the piece out cut it and let it lay for an hour or so depending on the weather just to let the flex all the way out -- also did you glue both sides the deck and the rubber?

I understand what you guys are referring to, but I meant after you've got the first half glued down and have the second half folded back. The spot right under where the fold was is where the adhesion was weak.

Use a 3" seam tape. I haven't used glue in years, too many problems. The seam tape and the flashing tape are easier, cleaner and faster than glue.