We are currently doing a waterproof deck so it doubles as a patio cover underneath. Its a water based product called 'Gaco' that you apply to the new plywood. Taking a total of 4 coats and seam taping all the joints and flashing. I would not want to rely on this simple elastomeric Latex paint for a coating over EPDM on an RV. However, I do think that more expensive Polyurethane products might be worth a trial test run by doing a small spot on your RV  to see if it peels after it cures. If you need a chisel to remove it and stays flexible it might be just the thing to add a coating more durable than the original EPDM roof. I think it worth a try as anything latex or water base is never used underwater. 

Edited September 5, 20195 yr by JAG1

All I can say is I will not follow the herd a second time for Dicor coatings. Extremely expensive and only lasted 3 years total joke. All that coating is now peeling up this summer and blowing off in the wind just sitting in the yard. Bought 3 gallons of the coating plus a gallon of the primer. Follow the directions closely. Even power washed the roof as directed in the instructions. Still peeling off.

 

Don't waste your time. 3 years and about $300 dollars worth of materials. 

 

I had way better results with the cheap hardware store coating on my old Dodge Jamboree and it lasted over 10 years before any problems happened. That generic coating worked awesome hardware store white roof coating much thicker material and sticks without primer. Put it on the same way wash the roof off good. Skip the primer and then roll on the new roof coating this stuff stuck really good and never peeled off!

1 hour ago, Mopar1973Man said:

this stuff stuck really good and never peeled off!

What was the "stuff"?

2 hours ago, IBMobile said:

What was the "stuff"?

 

Just generic hardware store roof coating that is white. Back in the day it was TruValue Hardware.

 

This is one I do remember..

Please you guys do not believe any labels, hype or news broadcast advertising. Use only a polyeurathane. You will see twenty years out of it. I'm serious it's very durable like a cummins vs a Yugo. Like night and day the roofers use it on high rise buildings and is compatible with EPDM. Believe me they don't go to the local Henry handy man hardware store to get it. 

 

You can go to any Paint store and get good elastomeric paint, It's common and less expensive that relabeled  but, it won't be as durable a a Polyurathane base coating. Anything labeled 'RV' on it is suspect

Edited September 8, 20195 yr by JAG1

26 minutes ago, JAG1 said:

Please you guys do not believe any labels, hype or news broadcast advertising. Use only a polyeurathane. You will see twenty years out of it. I'm serious it's very durable like a cummins vs a Yugo. Like night and day the roofers use it on high rise buildings and is compatible with EPDM. Believe me they don't go to the local Henry handy man hardware store to get it. 

 

Explain more... How about products links? I'm curious of this... 

Is this the type of polyurethane you're talking about?

 

https://lexiscoatings.com/polyurethane

That would be cool to be put together as a write up in the RV section.

20 hours ago, IBMobile said:

Is this the type of polyurethane you're talking about?

 

https://lexiscoatings.com/polyurethane

Now we are talkin' some pretty good roof coating here. I would like to know, in order to make double sure it's the right type of product, what you use to clean it off with. True polyurethane does not come off your hands easily. Once you touch it your sorry you did. Then when dry, the stuff is like a structural glue.... you need an air chisel to get it off. That is if the chisel can get through it. It will often just bounce and the poly laughs at the chisel.

Once polyurethane is applied it cures chemically and water will actually accelerate cure times. So if you get overnight condensation it will not hurt your application. I've used polyurethane caulking many times with great results and the coating should be the same, it is merely thinned down for easy application as a coating.

 

Anything claiming to be elastomeric paint is simply a water base acrylic or latex with an additive to increase it's ability to stretch. It lays on the surface and will not chemically bond like polyurethane will. Although with enough preparation and given perhaps a more compatible surface, there are cases where the water base products have shown some degree of success. I would not rely on it for the conditions an Rv is placed under. Wind, rain , heat and hail.

 

A good test for a product if your unsure, is to apply a small spot on the roof, letting it cure and see how easily it peels off. If it peels easily it is most likely something to take back to the store. Once peeled off you can then test its stretching ability by seeing if it tears more readily. Polyurethane is like a strong rubber band and won't tear or break till a long stretch is applied. Far better than any latex, by doing this you will notice the amazing difference.

Edited September 9, 20195 yr by JAG1

There are 2 or 3 roofing supply companies here in San Marcos I'll be going to check on this type of product.  I still haven't reroofed my 5er do to not having the time and the temps here being in the 90s just about every day.  If it looks doable I might put it on and try it out.  If it doesn't work I'll replace the roof like I was going to do in the first place. 

Be watchful that they don't try selling you a product that is a modified tar base. It needs to expressly state Polyurethane and cleans up with acetone or lacquer thinner. It would be nice also if it states that moisture or any condensation during cure time will accelerate the process of curing. That is how polyurethane reacts to water... it shortens the time required for curing.