Dicor EPDM, peeling sealant?

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Oldster

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I'm looking for some advice about how to handle an UGLY roof. I just bought a 2000 Coachman "Georgie Boy - Maverick" class c and I need to address the roof quickly. The EPDM appears to be in okay shape and there's no evidence of water damage, but the sealant is garbage:

IMG_2520 2.jpg

My question is: can I gently scrape away only the peeling sealant and reapply the Dicor sealant over the old/remaining/intact sealant, or do I need to remove all of the old sealant and get the roof down all the way to the EPDM before reapplying the sealant?

Time is a real factor and this only needs to last a month or two - I'm trying to ready this beast for a cross-country trip ASAP and I'll replace the whole membrane when time allows.

I'd also appreciate any advice on a more efficient way to scrape the sealant off. I'm using a putty knife and the going is slow... Thanks in advance for any knowledge or advice.
 
Nothing,,, and I mean nothing will stick to that mess.. Anything you put on an old peeling surface will just continue to peel with the old surface.. A very good & clean substrate is mandatory to get anything to do what you need it to ,, any "hurry"now will cost you more later and even greater labor..>>>Dan
 
You need to wash the entire roof to get rid of the mold which you have. A mixture of dish detergent and bleach with a course scrub brush with a long handle will do it. Washing the seams also but don’t over do it in case there are cracks in the caulking.
Then remove any old Dicor that is loose. If it’s still intact, leave it alone. Then go over everything with self leveling Dicor caulk.
 
Well, if that is the OE roof it is now 21 years old. Does anybody really believe a 21 year old roof that obviously has not been taken care of is worth spending 15 mintes on?
 
If the roof looks that bad I'm guessing the inside ceiling isn't much better. If you have extensive water damage inside fixing the roof may be throwing good money after bad.

If there is no water damage you should just tear off the old membrane and see what the plywood underneath looks like. If it is rotten then again, saving the RV may not be worth it. If it is in good shape your cheapest and quickest solution would be liquid rubber. It can be applied directly over dry plywood and takes the place of a new membrane. No more work than any roof coating but should last 15-20 years instead of 3. Refer to this recent post on this forum.
 
Thanks for the knowledge everyone. The plywood feels like it's in good enough condition with no obvious soft spots and the membrane is actually in pretty decent shape, especially when I factor in that this really only has to last the season. I'm about 2/3 of the way through scraping off the flaking old elastomeric and I'm feeling optimistic about the project.

Tell you what though, I wish I'd have asked before I bought the replacement elastomeric. That liquid rubber seems like the business... But since I already own $300 worth of it, I'm going for it with the new Dicor over the scraped clean/scrubbed clean membrane - fingers crossed.

This is a classic "you get what you pay for" type situation, but I don't mind some sweat, so...
 
I think you are mixing terminology. The Dicor sealant would only be on seams and around openings, i.e. its a caulk. The EPDM rubber membrane did not originally have any coating over it, so somebody added that later. It's usually called a "rubber roof coat" or similar verbage, and that is what is now peeling. The only Dicor sealant I see in that photo is around the roof skylight/vent and that doesn't look to be peeling.

So a former owner probably applied Liquid RV Roof, Hengs, Koolseal RV, Dicor Coolcoat, or similar roof coat product. And did a poor job of prep work, so now it's peeling.

In any case, I doubt if the membrane is salvageable. You can scrape the old coating away and then attempt to clean it well enough for a new roof coating to adhere, but I wouldn't bet much on success. If you try, I'd strongly recommend using an EPDM primer first. If it were mine, I'd tear off the old membrane and replace with new. And fix any problems in the substrate in the process.
 
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