RV Water Damage and Delamination Repair for San Clemente Owners

Fiberglass, aluminum and TPO roof membrane are all effectively waterproof. Water does not go through them. It goes around them, at the places where the manufacturer had to cut a hole or terminate a sheet. On a typical Class A there are somewhere between forty and eighty of those points, and every one of them is a maintenance item on a clock. Nobody sells you a coach with that list attached, and most owners find out about it the same way you probably did, which is a stain that appeared over a weekend.

The highest volume offenders are consistent across brands. The roof to sidewall termination, where the membrane wraps over the edge and gets clamped under a trim rail. Roof vent and air conditioner gaskets, which compress permanently and stop sealing after five or six years. The awning rail, which is a long screwed-on channel with dozens of fasteners through the sidewall. And windows, which almost never leak through the glass and very often leak at the frame flange.

Slide rooms deserve their own mention because they are the fastest growing source of water damage in modern coaches. A slide is a hole in your sidewall with a moving box in it, sealed by wiper and bulb seals that depend on the opening staying square. Let the opening rack a fraction of an inch and the seal compresses unevenly, and water enters at the top corner where nobody is looking.

The survey is the whole job. Get the map wrong and you replace four feet of subfloor next to six feet of wet subfloor you left in, and the customer is back in eighteen months with the same complaint and a bill they already paid once. We run four detection methods on every water job, and we run all four, because each one catches something the other three miss. No single instrument tells you the whole story on a laminated structure.

Pin and pinless moisture meters give us numeric readings on a grid, usually every twelve inches across floors and walls, referenced against a known dry area of the same vehicle. Absolute numbers matter less than the gradient. A reading that climbs steadily as you move toward a corner is telling you where the source is, even when every individual reading is technically inside the acceptable range for that material.

Thermal imaging works on temperature differential, so timing matters. Wet material holds and releases heat differently than dry material, and the contrast is strongest when the coach has been heated by sun and is cooling, or when we drive a differential deliberately. It will not see through a foil vapor barrier, which is why it never replaces the meter. Tapping the laminate with a plastic mallet finds delamination by sound: bonded panel rings tight, released panel goes hollow and dull. We mark the boundary in tape as we go.

A laminated RV wall is a sandwich: fiberglass outer skin, an adhesive layer, a foam core with luan or composite backer, framing members, then interior paneling. It is strong because the layers act as one. Delamination is that bond letting go, and once it releases in one spot it spreads, because the released area now flexes independently and peels the adjacent bond line every time the coach moves.

Water accelerates this dramatically. Moisture in the core softens the luan and attacks the adhesive at the same time. On the south and west walls in Orange County you also get thermal cycling: the panel heats hard in the afternoon, the trapped moisture turns to vapor, the vapor pressure pushes the skin outward, and by evening it cools and the skin does not fully return. That daily cycle is what turns a hand-sized bubble into a four foot wave over one summer.

The repair options are honest and limited. Small released areas with sound, dry core can be injection bonded and vacuum clamped. Areas where the core is wet, crushed or rotten cannot, and pretending otherwise is the most common bad repair in this industry. Those sections get cut out and the substrate gets replaced. Anyone quoting injection on a soft, wet wall is selling you eighteen months.

The floor is where gravity sends everything, so it is where the worst damage usually lives. RV subfloor is typically a laminated panel of plywood over foam over another skin, and when it wets it goes through three stages. First it swells and the flooring above it telegraphs a hump. Then it delaminates internally and feels spongy underfoot. Then the plies separate completely and it has no structural value at all, which is the soft spot people report.

Replacement means the flooring comes up, the affected panel comes out back to a sound edge over a supported frame member, and new material goes in. Where the rot has reached a cross member or an outrigger, that steel gets addressed at the same time, because covering compromised structure with fresh plywood is a repair with a countdown on it. Cabinets, furniture, and sometimes a slide mechanism have to be removed for access, which is where most of the labor hours actually go.

Wall substrate follows the same rule. Rotted luan behind an interior panel gets cut back to dry, sound material, framing members get inspected and replaced where they have gone soft, and new substrate is bonded in. Then, and only then, does anything cosmetic happen. Paneling, wallboard and flooring go last so nothing hides work that has not been verified.

A leak that has been running for two seasons in a closed coach has almost certainly grown something. Mold needs moisture, a cellulose food source and still air, and the inside of an RV wall cavity provides all three perfectly. In coastal San Clemente the marine layer keeps ambient humidity high enough that a wet cavity never really dries on its own, even during a long dry stretch in September. Owners frequently smell it before they see it, and that musty note when the coach has been closed up is worth taking seriously.

Our approach is containment, removal and verification. Affected porous material is removed rather than treated, because you cannot reliably kill growth inside saturated luan and foam. The area gets contained so spores do not distribute through the coach during demolition. Non-porous surfaces get cleaned and treated. Then the cavity is dried to a measured target with the meter before anything closes it back up. If we cannot get the readings down, we do not close the wall.

Freeze damage tends to arrive with owners who took the coach to Big Bear or the eastern Sierra without a proper winterize. Split PEX, cracked fittings, a failed water heater tank or a burst pump head puts a large volume of water into the structure quickly rather than slowly. That is actually the better version of this problem, because the damage is recent and the footprint is contained. It is also frequently a covered loss, unlike slow seam leakage.

The honest version is that the survey determines the price and there is no way around that. A soft spot at a slide corner that turns out to be two square feet of subfloor is a few thousand dollars. The same complaint on a coach where the moisture map shows wet material running eleven feet down the wall and across the floor is a different order of magnitude, and neither of us knows which one you have until we measure.

Our RV systems estimate is $150 and it is credited back against the repair if you authorize the work with us. Body and paint labor is posted at $210 per hour. Mechanical and electrical labor is $260 per hour. Below are the real bands. Insurance rarely covers gradual leakage, so most of this work is customer pay, and we would rather you know that on day one than in week two.

Body and paint labor is posted at $210 per hour. Mechanical and electrical is $260 per hour. Diagnostics run $285 per hour with a one hour minimum that is credited back against an authorized repair. Ranges below reflect jobs we have actually completed.