Ask Dave: There’s a peculiar seam on RV’s roof. Should I be concerned?

Hi, Dave,
It appears one of the sections at both sides of the seam on my RV’s roof have started to lift. It’s not much, but it caught my attention while I was on the roof using self-leveling roof caulking. What would you recommend? Thanks for being willing to speak with people and give advice. —Art, 2017 Jayco Jay Flight 28BHSW

Dear Art,
Since it is a 2017, I would contact Jayco first as it could fall under a 10-year roof warranty or structural warranty. I can’t tell if the seam is running lengthwise front to back of the coach or side to side. However, with the way the solar panels are positioned, I believe it is side to side. This would make more sense as the roof is typically built with 4’ x 8’ sheets of plywood approximately 1/8” thick on the upper portion with the TPO roof material over it. This looks like a separation at the seam between two panels.

When you step on one side of the seam do you feel or see it separating even more? Jayco uses vacubonding to pressure treat the roof components and it could be a faulty adhesive application. About the only way to really tell what is happening is to peel the TPO back and look at it.

First contact Jayco and selling dealer about roof

But before you do that, contact Jayco and your selling dealer to get it documented. They may want to have it taken in and slice the seam and pull back the material to see what is happening, as well. Then they can apply adhesive to the two sides, press it down to cure, and then run self leveling lap seal to patch it up.

It might just be cosmetic. However, if it keeps moving and pinching, it could tear open the TPO, then you have a big leak potential.

I would also inspect the mounting areas of the solar panels as they could have created a leak into the roof and the moisture traveled along the seam. Since the wood is particle board, it could swell up like this also.

How to do it yourself

If Jayco or your dealer will not do anything about it, I would cut in the middle of the seam and pull it back an inch and inspect the wood. If it is rotting or weak, you can reinforce it with a thin piece of sheet metal overlapping and flat-head screwing it in place. Then add adhesive to the TPO and reposition it. After that has dried, run a strip of Eternabond and cover with self-leveling lap sealant made for TPO.

Dave Solberg is a leading expert in the RV industry and author of the “RV Handbook” as well as the Managing Editor of the RV Repair Club.

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