Delamination – What It Is, How To Spot It, And Why It’s Important

(This article was originally written for and published in RV Daily Report on January 13, 2019.)

When purchasing an RV with a fiberglass wall, one of the most important things to watch for is delamination.

What is Delamination?

A fiberglass wall is a thin, flexible piece of fiberglass, laminated to a thicker, rigid substrate. The resulting wall should be stronger than either material.

Lamination isn’t just gluing two substances together. A vacuum is drawn on the whole wall, for the duration of the curing process, forcing the two materials together. A day or two later, the vacuum is released and the wall is a solid structure.

Delamination is what happens, when glue between the fiberglass and the substrate fails. Such failure is most often the result of moisture intrusion. Furthermore, once begun, delaminationmay spread, as moisture seeps further into the laminated structure.

Identifying Possible Delamination

Delamination appears as wrinkles in the fiberglass. In the above photo, you can see some of those wrinkles. But at that angle, the wrinkles might be mistaken for reflections. So rather than look straight on at the sidewall, look down the side, at about 10 to 30 degrees from parallel with the sidewall.

When viewed from this angle, the same delamination seen in the below photo, becomes very apparent.

Aside from cosmetic issues, delamination can weaken the wall structure. Also, moisture inside the wall can eventually lead to mold.

Dealing With Delamination

There are three ways for an RV buyer to deal with delamination.

  1. Cut out and replace the damaged wall section.
  2. Replace the whole wall.
  3. Walk away.

Let’s look at each of these options.

  1    Cut out and replace the damaged wall section.

By far, the most inexpensive repair method is to cut out and replace the damaged wall section. It’s also likely to be the most common type of delamination repair. However, this method creates two other possible issues – both related to the new seam that you end up with.

First, although modern fiberglass repair methods can create very secure seams, it is seams where you’re most likely to find moisture intrusion.

Second, the structural integrity of the wall may be weakened. A single-piece wall will generally be stronger than a wall with a seam. But depending on the location of the repair and the size of the replaced section, the seam may not weaken the structural integrity of the wall.

Cut out and replace canbe a very good repair method. But caution should be exercised, to insure that it does not weaken the wall or create potential moisture intrusion issues.

 2    Replace the whole wall.

Unless you have a lot of money to throw at it and have an extremely good reason to do so, this is probably not a very good option. You can get back to a single-piece wall – but at a price that is not generally cost effective. For this reason, it’s an option that most people will avoid.

 3    Walk away.

Due to the cost of repair and the potential for other problems, it may be best for the RV buyer to just walk away from the deal. But that’s a decision you have to make for yourself. Depending on the amount and location of the delamination, repair may be a viable option. Work with the seller. He may be willing to absorb some or all of the cost. Evaluate the cost, along with the potential for future moisture intrusion or structural issues. Talk to more than one RV repair service. You may find it reasonable to move forward. But you could just as easily find that walking away from the deal may be your best option.

You should always have your prospective RV purchase inspected by an NRVIA Certified RV Inspector. But there is no reason why you shouldn’t do some inspecting of your own, before you call the inspector. Your own preliminary inspection could save you the cost of a professional inspection, should you happen to find a show-stopper issue. But a professional inspection goes much deeper and has the potential to save you thousands of dollars in repairs. On the other hand, it might just give you a sense of security about the coach you are about to buy.

For the record, the client for the coach pictured in this article walked away from the deal, in large part, because of this issue.

John Gaver is the owner of RV Inspector Pro, based in Houston, Texas. He is an NRVIA Certified Level 2 RV Inspector. RV Inspector Pro inspects all sizes and types of RV’s, but specializes in Class A and Class C motorcoaches. For more information or reprint permission, John can be reached at our Contact page, by phone, at 713-253-1723, or by email, at

Buying a Gulf Coast RV after Hurricane Harvey

If you are planning to buy an RV that was anywhere near the Gulf Coast, between Corpus Christi, Texas and Lake Charles, Louisiana, during Hurricane Harvey, you should have it inspected by a professional RV inspector.

Some areas had tremendous winds, while other areas had flooding. Even RVs that were not is areas that were subjected to hurricane force winds or flooding, should be inspected for water incursion, because because days of wind driven rain can cause leaks around slides, windows, roof joints/seals, and roof penetrations.

If an RV has been damaged, even a thorough cleaning is likely to leave tell-tale signals of that damage, if you know where to look. Even a coach that did not get water inside, may have had the brakes sit in water for hours. This would present a safety hazard.

If you don’t want to hire a professional RV inspector, then here are some of the things you should look for.

  • Look under the coach, particularly on the tires and suspension, for a debris line, where floating debris may have been left, before the water went down. This could indicate possible brake damage. In such case, the brakes should be examined by a qualified RV brake specialist, to determine if such damage has occurred.
  • Feel inside the bumpers or under the fenders, for debris. Hidden debris inside the bumpers or fenders could indicate that high water deposited that debris there and thus indicate possible brake damage. In such case, the brakes should be examined by a qualified RV brake specialist, to determine if such damage has occurred.
  • Carefully examine the inside of all cabinets and closets, with a bright flashlight. You will be looking for water staining or swelling of the wood and any water staining of padding or carpet inside the cabinets. This may or may not be significant. But if you find such indications, further examination is advised.
  • Look at the floor areas, near the front and rear of each slide. Examine these areas, both with the slide in and with the slide out. You will be looking for water staining or other indication of water incursion. This may or may not be significant. But if you find such indications, further examination is advised.
  • Examine the storage bays directly below the front and rear of each slide. You will be looking for indications of water incursion, dripping from the slide edges. This may or may not be significant. But if you find such indications, further examination is advised.
  • Look inside the engine and generator compartments, for signs of water debris that may not have been cleaned off, when the RV was washed. Keep in mind that this is an engine compartment. It gets dirty. So debris inside the engine or generator compartment may or may not be significant. But if you find such indications, further examination is advised.

The above list is, by no means, intended to be comprehensive. A professional RV inspector will use specialized tools, to make further determinations. I personally use a large (10 inch) inspection mirror, to see under the RV, a small (one inch) inspection mirror, to see behind interior obstructions, and a bore-scope, to see inside and around obstructions where even inspection mirrors won’t fit. A professional RV inspector will also examine the roof, for signs of potential leaks or damage to air conditioner(s), TV antennas, and other roof-mounted equipment.

Most of the RV dealers in the Houston area survived the storm with little or no damage. I’m sure that most dealers will check out their inventory, before offering their coaches for sale, after the storm. But they have hundreds of RVs to inspect and can’t spend all day on each RV. For that reason, it’s possible that they could inadvertently overlook some minor hidden damage. By contrast, a professional RV inspector will spend 6 to 8 hours examining just one coach – the one you plan to buy. Without a comprehensive inspection, you cannot be sure that the particular coach you plan to buy did not sustain some hidden damage.

Is it safe to buy a Gulf Coast RV after Hurricane Harvey?

Should you have it professionally inspected?

Every RV, used or new and regardless of where it is purchased, should be inspected. Hurricane Harvey is just an additional reason why you should have your prospective RV purchase inspected. Certainly, an RV inspection cannot guarantee that an RV is completely free of defects or damage. But a professional RV inspector knows what to look for and has the requisite tools to make determinations beyond the obvious. What a professional RV inspection offers, is a significant comfort level with your RV purchase, well beyond what you might otherwise achieve on your own.

To find an NRVIA certified inspector in your area, follow this link.

John Gaver, of RV Inspector Pro, is a National RV Inspectors Association (NRVIA) Certified Level 2 RV Inspector.

Copyright 2017 John Gaver
The copyright holder grants third parties the right to re-publish this article only in whole and un-modified, including links and this notice.