Best Roof Coating

TurnThePage wrote:
JBarca is a smart guy and I wouldn't ever consider debating with him. But the Heng's acrylic latex coating I put on my EPDM roof, that by the way has lots of Eternabond tape, is holding up quite well. I don't know about water ponding as my roof is peaked so it all runs off. The only place I've ever seen any ponding is on the high side edge of the refrigerator vent, and that area is as intact as the rest of the roof. As it's easy to apply and is holding up well, I expect it'll be my go to product if recoating is ever again necessary. Maybe geography plays into it, I dunno. My trailer lives outside pretty far north in the inland northwest. Snowy winters and sunny summers with generally low humidity. Just reporting my experience.

Hi Turnthepage,

Thanks for the good words. I know your screen name from over the years as a respected one. I am very open minded and the learning never stops. Lets compare notes and I will clarify some of my comments.

Let start with the coatings not sticking to Eternabond. When I bought my small batch of silicone coating from Crazy Seal, I quizzed them a lot about how the product works and if it will adhere to Eternabond. They told me it will not create a long term bond. They have seen it lift over time. There are work arounds for this, they just clarified their product will not bond long term to Ebond. In 2010 I Ebonded my entire camper and the roof is still pristine for 16 years, just the shed layer of the EPDM is thinning. The Ebond saved the seams of that camper which is why I needed to know if the silicone coating would adhere. I have a plan for this when I do the large open areas in the future, but the Ebond will remain on the camper, just not coated.

I camp with a group from the Sunline club, the brand camper I have and others I have restored. There are several of us that talk a lot and we see what each has done to the camper when we meet up.

Last summer we camped with a friend who used the Dicro acrylic coating to restore his 21 year old camper EPDM roof 3 years ago. He had Ebonded all the seams prior and he coated over them. During year 3, he started to see the coating lifting off the Ebond. That for sure peaked my interest. I went up on the roof from the side to see what he was talking about. Here are the pictures.

The gutter rail area with Ebond under the coating.


A close up so you can see better


A second area


Close up


It took 3 years for this lifting to start. The rest of the camper does not show this yet, but it will be watched as the years go on.

This adds some context to what I was saying. There is something about the slickness of top layer of Ebond that coatings have a hard time adhering to it long term. This may not be an immediate no stick thing. Pending the coating, it may not even be a problem if the coating lift stops at the edge of the Ebond. The point being, it may not adhere long term.

How long ago did you coat your roof? The camper in the pics lives in NW Ohio with mid west humidity, snow and freezing temps. He does put his camper in storage for the winter months. It lives outside the rest of the time. Please report back as the years go on yours if you see it lifting. It may be Heng's has something different or it just takes longer for the effect to show up.

To the ponding water comments, some non walk on camper roofs have the roof support system to allow the membrane to sag slightly, and water ponding can occur in those areas. A seasonal camper what never travels, would be large issues as the pond will never drain until it all evaporates.

See this pic from a 2005 camper roof I was doing some repair on for a friend who just bought it from a dealer. The caulk failed on the front seam, a leak started, then someone went up and put more caulk on. Look at the blackened molded area stain on the rubber roof. You can see where the water was ponding. The EPDM rubber was under water. It EPDM survived well, the front seam with bad caulk leaked.


If a camper has a roof structure that allows ponding like that to happen, it should be realized as it may be a coating problem. The coating has to handle being under water for periods of time that may take days to evaporate off. This is especially a concern on a seasonal site where the camper never moves or a camper stored between camping trips.

Some acrylic coatings have a characteristics of breaking down, again over time, due to being submerged under water a long time. A camper that sheds water all the time or one that is towed a lot, may not have an issue other then when it is stored and it rains. The ponding issue it something to confirm with the coating manufacture their coating is not affected by it to make sure you are OK. I have no data to report what a long time is.

Hope this puts the comments in context.

Thanks

John