Coating over old PVC type membrane

Hoping someone can give me some advise on what we might use to coat all or parts of a barrel roof that has some type of plastic roofing. We think it might be Sarnifel but there is nobody that knows. The membrane is about 30 years old so they have gotten their moneys worth out of it but they don't have the money to redo the roof. Its about 5000 square feet. The membrane has a fiberglass mesh that is exposed over large sections and the thin undercoat of plastic is starting to split and leaking. I have no experience with coatings on this type of roof and am looking for any advise I can get. Anybody willing to help?

@clvr83 the full story (in pictures) on the EPDM lap/Seam Tape Topic http://forum.rooferscoffeeshop.com/view_thread.asp?threadid=46030&forumid=8&pn= but basically some idiot had painted acrylic paint on the corners and the seams and I couldn't get it off, so although I redid the seams on the flat, I chose the easy option for the corners and seams on the upstands, and yeah a bit to do with cost for the customer, the labour to redo those corners would have been quite high, and I don't think they were causing any leaks anyway, so the Silcoat just a precaution.

-Vaa Fakaosifolau

Thanks for sharing. Quite interesting to see the process from begining to end. 

Here is the S-20 silicone going on over TPO. Notice it is nice and bright white and shiny. This TPO roof gets over 300,000 sq. ft. of silicone.

Vaa, no rain won't wash it off, it is 96% solids and the other 4% is not water. In fact you have to be very careful about humidity and letter any moisture get to it as it is moisture-cured. If rain hits it is cures immediately.

Thanks for the help here. I did talk to Bobby Anderson. This does sound like the product I need. Now all I have to do is sell the repair work. Thanks all!

I use the Conklin products. They have a cleaner that is just great. It takes off the oxidation right off the EPDM and it cleans modified and built up roofs like magic. they also have what they call a "tack coat" to apply before you put down the coatings. it is sticky as heck and adheres to the substrate before you apply the top coats. very good! It is an acrylic system so it is water soluble but it dries fast. I like it especially for metal roofs.

That's the same primer we use over TPO.

They have a solvent-based silicone called S-10. I can imagine that would be a lot tackier an d attract dirt.

Vaa, not sure what you are doing different but that's not our experience at all. Did you use the S-20?

You will find very few places on earth more dusty than Lubbock, Texas. If any. That simply hasn't been an issue because the silicone coating films over very quickly and after that nothing on God's green earth will stick to it, except more silicone.

Ours are very bright white.

Roofguy Said: Yes, works over EPDM too. We prime just about everything coz its just 6 cents a foot + labor and cheap insurance. Other guys just do an adhesion/pull test.

So, after cleaning.... what primer are you applying to epdm pre gaco..?

Yes, works over EPDM too. We prime just about everything coz it's just 6 cents a foot + labor and cheap insurance. Other guys just do an adhesion/pull test.

GSD Said: Im going to agree with the Gaco, Ive been coating old Durolast and its been working great. covering lots of old spider webbing leaks.

Looks like a decent repair option for old membranes. do you have to put any type of primer before applying the Gaco..? What about epdm. Will this Gaco stuff work on epdm..?

I'm going to agree with the Gaco, I've been coating old Durolast and its been working great. covering lots of old spider webbing leaks.

Vaa said "Bit of a worry about that PVC failing and the mesh showing through clvr83, how old was that?"

No clue, these guys don't give me any information like that. I assumed it was from grease because no other spots are worn through like that except near the grill exhaust to the drain.

Another note: When I put some of this on in ~90 degree weather, it dried before a small rain hit us an hour later. In 50 degree weather it was still wet a few hours later.

No doubt about it, silicone is slick as snot. It is slick when dry, and like ice when wet. We intend to embed a few granules 5' wide on edges where someone might be at risk falling hanging Christmas lights or something.

And, nothing sticks to silicone but silicone. This will be leverage with adjusters who want to knock our price down.