OT, but business, what glue sticks to EPDM?

I had a synthetic rubber roof put on the shop a few years ago. The roofer neglected to tell me he had never done one before and got a lot of wrinkles in the first sheet. It still kept the rain out, so it was not that big a deal, but now a raccoon is eating the tops off the wrinkles. Why, I have no idea, but there are many tooth marks and raccoon tracks around them. The roofing supplier has two types of glue, one for fastening the rubber down to the sheeting and another for sealing seams where the sheets overlap. The explanation for the two is that the first will not hold under water, but does a better job in the middle of a sheet where water is kept away. I saved some of the left over rubber and seam glue for patching, which I really need now. The problem is that the glue sticks when I apply it, but a few months later lets go and the leaks return. There has to be a better way.

Bill

Cut out and patch the worst wrinkles if they run to a seam. Since this is a repeat repair job you are no longer gluing EPDM to EPDM - you are gluing old glue to old glue. You might just want to patch the wrinkles and the existing seam, too.

dp said:

Cut out and patch the worst wrinkles if they run to a seam. Since this is a repeat repair job you are no longer gluing EPDM to EPDM - you are gluing old glue to old glue. You might just want to patch the wrinkles and the existing seam, too.

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I split the wrinkles down the center, lapped the material over so it was down flat, put glue on the overlapped area, and glued a patch over the joint. That isn't the problem. The glue applied to a clean dry surface lets go after a few months. Surface preparation such as scuffing it like you do on an inner tube patch, doesn't help. The glue simply doesn't bond whether it is to a new surface, old glue or whatever. The leak will be stopped for a while, then starts again. I can pull the patches off with minimal effort and there is water under them. I need a different glue.

Bill

The roofers I've seen applying EPDM membrane roofing use something like a solvent based contact cement. Smelled like it.

Google the topic using EPDM installation instructions and variations. You don't want shade tree advice when it comes to keeping the rain off your treasures.

First find out what the synthetic rubber polymer is then contact 3M. 3M in my expience is helpful and knowlegeable. They most likley have an that will fix it down tighter than nun's %)*&#.

For the repair cut a slit (no pun intended) so air can escape when the bubble is flattened as well as let the air out and create a place to introduce the adhesive. Place a weight on top so pressure is applied while cure take place.

Goes with out saying follow the instructions to the letter being esspecially mindfull of working temps of the adhesive surface prep.

Or go to Home Depot and by a blue tarp and on the way home ammo for the .22 hornet (just kidding I love animals).

How are you useing the glue? Are you letting it dry before you stick it together? Follow the directions to the letter.

Forrest Addy said:

The roofers I've seen applying EPDM membrane roofing use something like a solvent based contact cement. Smelled like it.

Google the topic using EPDM installation instructions and variations. You don't want shade tree advice when it comes to keeping the rain off your treasures.

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EPDM primer? Primer for joining EPDM membrane liner 250ml | Dam, Lake and Pond Aeration | Fountains | Water Treatments and Testing | Biological Filtration | Lake Management

The glue needed is a solvent-based adhesive. Typically you need to apply that type of adhesive to both sides of the joint, then wait a bit, then make the joint. The spec sheet I found says 5-50 minutes before joining.

Alternately, splice tape appears to be available. No clue how that works. SAG 180 posted a link to a primer used before applying it, so i assume that's probably needed.

Forest- The glue is a contact cement from the roofing supply company and supposedly recommended for seams. I am asking for outside advice because the official material isn't working, either for these patches or for other places. Flashing using it has also failed in spots.

dough8cat- The material is ethylene propylene diene monomer, although the EPDM Roofing Association website calls it ethylene propylene diene terpolymer, a name I hadn't seen before. I am doing what you describe re slitting, weights, etc. The other places where it has come loose have not had as serious consequences, but in general it has not worked well. The problems are at the back of a 3000 sq. ft. building because they naturally installed the rear section first and made the most mistakes there. The building is typical of the so called store fronts in older cities with brick walls that extend above the roof with tiles on them and a flat roof pitched to the rear. In a heavy rain all that water rolls over the area with the holes. A tarp would have to cover the whole thing or be sealed down to the roof. The raccoon hasn't been back since last fall. If it was swallowing the EPDM, I doubt that it is still with us.

Heavey Metal- Letting it dry works better than putting the patch on wet, but "better" is a relative term, here meaning not quite as poorly.

Sag- I think you may have the answer, a different system. Nobody said anything about joining tape or primer in the past. Maybe the rest of the world has had similar problems and developed a new solution. It must be available in this part of the world, too.

Bill

sniper1rfa said:

The glue needed is a solvent-based adhesive. Typically you need to apply that type of adhesive to both sides of the joint, then wait a bit, then make the joint. The spec sheet I found says 5-50 minutes before joining.

Alternately, splice tape appears to be available. No clue how that works. SAG 180 posted a link to a primer used before applying it, so i assume that's probably needed.

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I was typing while you posted. You are correct. Many years ago, I did a study of Velcro attachment techniques and found that the contact cement recommended actually gave a stronger bond if applied wet, clamped, and given a few days for the solvent to migrate out. That doesn't seem to be the case here.

Bill

W. W. Grainger sells the repair tape and primer. I hope that will settle the issue. Thanks for the advice.

Bill

EPDM roofs are often used on RV's. I had one on mine that was aging and getting worn spots from age and some tears from branch contact, etc.

RV supply companies sell a tape for repairing EPDM roofs that works pretty well. Its available in different widths. I patched all my holes and tears with it and it worked really well.

Paul T.
Power Technology