Wednesday, September 28, 2022


Ask Dave: Why is the sidewall on my trailer “crinkling”?

Answers to questions about RV Repair and Maintenance from RV expert Dave Solberg, author of the “RV Handbook” and the managing editor of the RV Repair Club. This column appears Monday through Saturday in the RV Travel and RV Daily Tips newsletters. (Sign up for an email reminder for each new issue if you do not already receive one.) Today Dave discusses sidewall delamination, which causes “crinkling.”

Dear Dave,
I have a 2007 18-foot Fun Finder and the sidewall on the front portion of it is crinkled. Some people say it is because it wasn’t glued correctly. I would like to find out how to repair it. Thanks. —Leonard

Dear Leonard,
What your trailer is experiencing is called delamination, which is the separation of the outer skin material. This can be caused by incorrect gluing. However, it is most often caused by moisture penetration from a seam that was not sealed properly. The moisture weakens the adhesive between the outer skin and the lauan backing and then air bubbles or crinkling occurs. There are several points that need to be inspected at least yearly as temperature changes, UV degradation, and even road vibration can cause the sealant to split or pull away.

Most delamination is on the sidewall

In motorhomes you see delamination typically on the sidewall of the unit. This is because the roof-to-sidewall joint lets in water, which travels down the sidewall. Trailers typically have the delamination in the front fiberglass cap. This is because the seal between the roof material (usually rubber membrane) and the hard fiberglass front cap is the source of the moisture penetration. With temperature changes, the rubber material and fiberglass expand and contract differently. If not inspected and addressed, the sealant separates from the “J” channel used to allow the expansion and contraction, then water penetrates and delamination happens.

How do you repair sidewall delamination? Not easily, as the original panel was layered and adhesive added during each application. Then it’s either pinch rolled or, more likely, set into a large bladder and vacuformed with pressure for several hours.

How you may be able to repair sidewall delamination

Depending on the severity of the delamination, you might be able to remove the sealant at the “J” channel and loosen the fiberglass of the delamination. You would then try to get some adhesive back in between the materials and then add pressure. If it’s several small spots, I have seen repair facilities drill a small hole in the middle of the bubble and squeeze in some adhesive and again apply pressure.

Make sure you get adhesive designed for this application. You can get it at a dealership or auto body shop. Then, make sure you properly seal the original cause of the damage.

Read more from Dave here

Dave Solberg worked at Winnebago for 15 years developing the dealer training program, as marketing manager, and conducting shows. As the owner of Passport Media Creations, Dave has developed several RV dealer training programs, the RV Safety Training program for The Recreation Vehicle Safety and Education Foundation, and the accredited RV Driving Safety program being conducted at rallies and shows around the country. Dave 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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1 year ago

I live in the desert of Arizona, I have had a few trailer walls de-lamenate. I think it was from the heat because we are very dry here, also temperatures can get above 120.

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