Maintenance for Silicone Roof Coating on EDPM

Question

So back in 2008 I replaced my EDPM roof with fresh EDPM and Eterabonded the heck out of it to try and do a "once and for all" kind of job. I documented it on this forum but older posts seem to have been lost. Of course all things age and Eternabond is not eternal and has a couple layers now. And, 17 years later, the EDPM material is loosing it's white coating. So time to act before the underlying black material also goes.

I am considering putting on Henry's Tropicool Silicone coating on the roof to get some more years out of before doing a re-roof and probably have to re-do the wood arches and thin plywood in the roof as some areas are sagging a bit.

I do have some small experience with Tropicool. About 7-8 years ago, my awning was cracking and flaking on the area exposed to the elements when rolled up. So on a whim I tried Tropicool on that area. It has held up well, and still doing it's job protecting the exposed part of the awning. So Tropicool stands up to the Southern California sun well. A lot better than the awning material.

My question for those who have used Tropicool, how has maintenance been? Does the spray can of silicone patch material work well? Are there any other products to used for leaks? How do you handle separation or cracks around vents, etc? I will be aplying over existing Eternabond taped areas.

I do understand that it is a one way trip to silicone land, and only more silicone will be able to adhere to the Tropicool.

1996 Fleetwood Prowler 22LU, we purchased it used in 2006.

naturist · Answer

I put on Tropicool a year ago, including over some Eternabond on an EDPM membrane and got good results, There was one leak still, however, which I traced to the edge of one of the Eternabond strips, where evidently two coats of Tropicool did not manage to seal. It seems the Tropicool coating was repelled by something about the Eternabond edge, and left an uncoated seam. I used a silicone caulk I bought at Lowes to caulk over that edge, and it seems to have bonded well and stopped the leak. I have no clue why that one spot failed to coat, and no others have proven a problem, but you might want to watch out for a similar issue.

The trailer lives most of the time in storage under some black walnut trees, and thus it is impossible to keep black stains completely at bay. But a soft brush and Simple Green does seem to work cleaning the Tropicool layer.

dcairns · Answer

Thank you for that reply. I wonder if a "schmear" of silicone caulk on the edges of the eternabond before Tropicool might be helpful for me.&nbsp; I do plan to do some sort of surface roughening to the white backing of the eternabond to help the Tropicool adhere.&nbsp; But there are plenty of places where the white tape has cracked and falling away.

dalo · Answer

I own a 2003 Alumascape trailer with EPDM roof.&nbsp; Twenty years ago I put Eternabond tape on all the roof seams.&nbsp; Four years ago I found Henry's Tropicool at Home Depot and bought 2 cans .9 gallon each.&nbsp; It went on very easily with a roller and looked good.&nbsp; I tried 2 of the aerosol spray cans and they were a bust.&nbsp; The product was too thick to be sprayed and I felt that was a waste of money.&nbsp; Just recently I noticed some small areas starting to peel off.&nbsp; I believe I should have applied 2 more .9 gal cans when I did my initial application.&nbsp; One other problem I had was my roller I used to spread it was losing fibers.&nbsp; Make sure you get a good quality roller.&nbsp; BTW my trailer is 25' long.

dcairns · Answer

Thank you for the reply. I have a slightly smaller trailer with a sloped front end. So the actual roof to treat is like 8x20. So I was thinking the Henry 887 in a 5 (4.75) gallon bucket. Thanks for the tip about using a good roller.

Just found this at Henry's website:
https://dam.henry.com/m/7a41340dd62b6fc3/original/Tropi-Cool-RV-Brochure-Spread-USEN-LR.pdf

They recommend a kind of two step process:
TO PREP
Henry 884 Tropi-Cool 100% Silicone Roof Sealant
or
Henry 885 Tropi-Cool 100% Silicone Seam & Repair Roof Sealant
TO COAT
Henry 887 Tropi-Cool 100% Silicone Roof Coating

I had not heard of the 884 and 885 before. I will need to look into that. I am not sure if they are saying to coat the whole roof with 885 or use is as spot treatment for difficult areas. The 884 caulk does looks handy for treating leak prone / suspect areas before the 887 coating. I intend to give the roof a pressure wash and scrubbing with something that can take the shine off the Eternabond for better adhesion. The cooler weather of fall is coming, so I need to read up so I can take advantage of the nice dry weather to do the job.

dalo · Answer

Good luck with your repair.&nbsp; I think my biggest mistake was not buying the 5 gal. bucket of Tropicool 887.&nbsp; I started by washing the roof, then applied the 884 caulk to areas that the Eternabond tape was lifting.&nbsp; I used the Tropicool Stop Leak (in a spray can) around a few irregular shaped areas such as a skylite over the shower.&nbsp; Not the whole skylite, just the edges where it meets the roof.&nbsp; That can of 880 Stop Leak does not contain much product.&nbsp; I am thinking about doing my whole roof again with just the 887.&nbsp; However, I am in my 70's and don't really like being on the roof anymore.&nbsp; Good luck!

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Maintenance for Silicone Roof Coating on EDPM

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