Delamination is the fiberglass outer skin losing its bond to the substrate behind it. It appears as a bubble, wave, or ripple in the sidewall. The cause is water sitting between the layers. Repairing the skin without correcting the water entry point guarantees the failure returns.
Why this fails in the first place
Before anything gets quoted we work out why the damage happened, because the repair is different depending on the cause. On fifth wheels, travel trailers, and Class A and Class C motorhomes, the same visible symptom can come from several different failures, and fixing the wrong one means the vehicle comes back.
RV sidewalls are a sandwich. The outer layer is a thin fiberglass skin, usually gelcoated or painted. Behind it is a substrate, historically luan plywood and more recently Azdel composite. Behind that is the framing, either aluminum tube or wood, with block foam insulation between the members. Azdel is a meaningful upgrade because it does not absorb water and does not rot, so an Azdel coach that gets wet loses its bond without losing its substrate.
Window and door frame seals: The single most common entry point. The butyl behind the frame flange dries out, and water runs down inside the wall rather than off it.
Clearance light and marker gaskets: Small, numerous, and routinely ignored. Every one is a hole through the skin with a gasket that ages.
Roof to sidewall seam: The seam takes constant flex. Once the sealant opens, water enters at the very top of the wall and travels the whole height of it.
Awning rail fasteners: The rail is through bolted into the sidewall. Those fasteners carry load and work loose, and each one is a direct path into the laminate.
Slide out corners: Where the slide opening meets the sidewall is the highest movement area on the coach and a frequent origin point.
What owners notice first
Most of the vehicles that arrive here from Buena Park have been showing one of these signs for months. Catching it at the first sign is usually the difference between a contained repair and a structural one.
Visible bubble or wave: Sight down the sidewall in raking light. Delamination shows as a ripple long before it is obvious head on.
Hollow sound when tapped: Tap along the wall. Bonded laminate sounds solid. Delaminated areas sound hollow and the note changes at the boundary.
Soft spot under pressure: Press firmly. If the skin moves independently of the wall behind it, the bond is gone.
Staining inside on the wall panel: The interior side of the same wall often shows a tide line before the outside bubbles.
Musty odor: Wet luan inside a sealed wall smells, and the smell returns after airing out because the source is still wet.
Our repair sequence
Every job is written up before a tool comes out, photographed at each stage, and documented in a form an adjuster can read. Body and paint work is billed at $210 per hour and mechanical and electrical at $260 per hour, both posted publicly so you can check the math on any estimate we hand you.
Map the affected area. We tap test and moisture meter the whole wall to establish where the delamination actually stops, which is normally well past what is visible.
Find the water source. Water testing traces the entry point. Repairing the wall without this step is the reason most delamination repairs fail twice.
Open an inspection port. We cut in to see the substrate condition. Injection is only appropriate if the luan or Azdel behind the skin is still sound.
Repair or replace substrate. Sound substrate gets injected with adhesive and vacuum clamped flat. Rotted substrate and corroded framing get cut out and replaced.
Rebond and clamp. The skin is bonded and held under even pressure while the adhesive cures, because uneven clamping leaves a visible ripple permanently.
Refinish and blend. The repair area is refinished and blended into adjacent panels so it does not stand out against sun faded gelcoat.
Parts and materials that matter here
RV sidewalls are a sandwich. The outer layer is a thin fiberglass skin, usually gelcoated or painted. Behind it is a substrate, historically luan plywood and more recently Azdel composite. Behind that is the framing, either aluminum tube or wood, with block foam insulation between the members. Azdel is a meaningful upgrade because it does not absorb water and does not rot, so an Azdel coach that gets wet loses its bond without losing its substrate.
For injection repairs we use a structural adhesive designed for the fiberglass to substrate bond, applied through a controlled grid of injection points and pulled flat with vacuum. For panel replacement we source the closest available skin and refinish, because factory matched gelcoat panels for older coaches are usually long discontinued.
Why this comes back when it is done badly
The most common failure is injecting adhesive into a wall with rotted luan. The adhesive has nothing to bond to on one side, the panel looks flat for a season, and it bubbles again as soon as the weather turns. Cutting an inspection port first is what separates a repair from a delay.
The second is fixing the wall and leaving the leak. We regularly see coaches where the skin has been repaired twice at the same spot by two different shops, and nobody ever water tested the window frame six feet above it.
The third is refinishing the repair without blending. A perfectly bonded panel that is a shade off from the wall around it reads as damage from thirty feet away, which matters if you ever sell the coach.
How this works with your insurance claim
Delamination caused by a sudden covered event is generally payable. That includes hail that broke a seal, a collision that opened a seam, and a falling branch. Delamination from years of gradual seal failure is normally excluded as wear and maintenance.
Because the two look identical once the wall is bubbled, cause documentation is everything. We photograph the entry point, the water path, and the moisture boundary, and we write it up in the terms an adjuster is required to evaluate.
We bill every major carrier direct, so you are not fronting the repair and waiting on a reimbursement. Under California Insurance Code section 758.5 your insurer cannot require you to use a particular shop. You pick the shop, they pay the claim.
Getting the work done from Buena Park
Our facility sits at 23281 La Palma Ave, Yorba Linda, CA 92887, roughly 13 miles and about 20 minutes from Buena Park using the 91 and the 5. All work is performed here in the 35,000 square foot shop, where we have the frame equipment, the lift capacity, and the paint booth. We do not run route service, because this work cannot be done properly in a driveway.
A written estimate is $150 and is credited against the repair once you authorize it. Bring the vehicle in, or call (714) 909-1444 and we will tell you what to expect before you drive out.
What this work typically costs
Real ranges from our posted catalog, not a marketing number. The spread is wide because the scope is wide, and where your job falls is determined at teardown rather than guessed at over the phone.
| Work | Typical range | Shop hours |
|---|---|---|
| Fiberglass cap repair, front or rear | $750 to $12,000 plus | 4 to 60 |
| Aluminum skin and sidewall replacement | $2,500 to $25,000 plus | 16 to 120 |
| Delamination repair, sidewall, roof, or slide face | $1,500 to $20,000 plus | 10 to 100 |
| Water damage restoration and subfloor replacement | $750 to $15,000 plus | 4 to 60 |
Sales tax of 7.75 percent applies to parts and materials. Labor is not taxed. See the full posted rate card.
Frequently asked questions
Can RV delamination be repaired, or do I need a whole new wall?
Both happen. If the substrate behind the skin is still sound and the area is contained, we inject structural adhesive and vacuum clamp the panel flat. If the luan has turned to pulp, injection has nothing to bond to and the panel has to come off so the substrate and any corroded framing can be replaced.
How much does delamination repair cost?
Roughly $1,500 to $20,000 and up, at 10 to 100 shop hours. A contained single panel injection is at the low end. A full sidewall with rotted substrate, corroded framing, and a full refinish is at the high end, and that is why finding it early matters so much.
Will delamination get worse if I ignore it?
Yes, and it accelerates. The separated area lets more water in, the substrate keeps rotting outward, and the framing behind it corrodes. A repair that would have been one panel becomes three, and once the framing goes it stops being a skin repair and becomes structural.
Does Azdel prevent delamination?
It does not prevent it, but it changes the outcome. Azdel is a composite that does not absorb water and does not rot, so an Azdel coach that leaks loses the adhesive bond without losing the substrate. That usually means the repair is an injection and rebond rather than a full panel replacement.
Do you work directly with my insurance company?
Yes. We bill every major carrier direct, including Progressive, GEICO, State Farm, AAA SoCal, Mercury, Allstate, Wawanesa, National General, Foremost, Liberty Mutual, Good Sam, and The Hartford. We write the estimate, photograph the damage, submit supplements when hidden damage turns up, and deal with the adjuster so you do not have to.
What does an estimate cost?
A written estimate is $150 and it is credited back against the repair once you authorize the work. An in depth diagnostic is $285 for the first hour and is credited the same way. We charge for estimates because a proper one takes real shop time, and that keeps our schedule filled with actual repairs.
Do you come out to Buena Park, or does the vehicle need to come to you?
The vehicle comes to us. Everything happens in shop at 23281 La Palma Ave, Yorba Linda, CA 92887, about 13 miles from Buena Park on the 91 and the 5. We do not run route service. Frame work, structural repair, and refinishing need the equipment and the booth, and nobody can do that job correctly in a parking lot.
What are your posted labor rates?
Body and paint is $210 per hour, mechanical and electrical is $260 per hour, diagnostics and programming is $285 per hour with a one hour minimum, and detail is $95 per hour. Paint supplies bill at $55 per paint hour and body supplies at $5 per body hour. Sales tax of 7.75 percent applies to parts and materials. Labor is not taxed.
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Last reviewed by the OCRV Center shop team.