--- title: "Fiberglass or Aluminum RV Sidewall: Repair Compared" description: "Laminated walls hide damage in the glue line. Aluminum walls show it where it happened. Ten criteria, real labor hours and when each construction wins." focus_keyword: "fiberglass or aluminum sidewall which is easier to repair" canonical: https://ocrv.me/comparisons/fiberglass-vs-aluminum-sidewall/ kind: comparison updated: 2026-07-29 source: OCRV Center --- # Laminated Fiberglass Against Aluminum Skin on RV Walls > Laminated walls **hide damage in the glue line** and spread it sideways. Aluminum walls show damage where it happened. That single difference drives a **five to ten times** labor gap on large repairs. ## Is a fiberglass or an aluminum RV sidewall easier to repair? Aluminum is easier and cheaper to repair because damage stays local and sheet stock is a commodity. Laminated fiberglass rides better and insulates better but spreads bond failure past the impact. Both come through our Yorba Linda bays weekly from owners across Rancho Santa Margarita. - Aluminum sheet sections are let in between existing battens - Laminated panels have to be sounded before anyone can quote - A reskin runs 40 to 120 body hours; a sheet section runs 12 to 40 - Laminated walls are quieter and warmer while they are intact ### Key facts | Item | Value | | --- | --- | | Body labor rate | $210 per hour (Both constructions bill from the same department) | | Laminated large repair | 40 to 120 body hours (Skin removal, core replacement, rebond and refinish) | | Aluminum large repair | 12 to 40 body hours (Sheet section let in at a batten with sealant and fasteners) | | Diagnostic tool | Tap test and pin meter (Required on laminated walls, optional on aluminum) | | Written estimate | $150 (Credited in full against an authorized repair) | Two units arrive with the same scrape from the same canyon road. One is a laminated fifth wheel, the other an aluminum skinned travel trailer of similar age. The scrape looks identical from ten feet. The estimates are not close, and the reason has nothing to do with brand quality or how hard the driver hit the rock. It is a property of how each wall carries load. The table on this page is the version we walk owners through at the counter. What follows explains why each row reads the way it does, and where the cost curves for the two constructions actually cross. ## What each wall system physically is A laminated wall is one part. Gelcoated fiberglass on the outside, block foam and an aluminum cage in the middle, an Azdel composite or lauan plywood face on the inside, and the whole sandwich pressed together with adhesive under vacuum at the factory. Structural continuity comes from the bond, which is why the industry term for its failure is delamination rather than cracking. An aluminum skinned wall is an assembly. Studs of wood or aluminum, insulation between them, an interior panel, and exterior aluminum sheet fastened over the outside with a batten covering every vertical seam. Nothing is bonded, everything is mechanically fastened, and each piece can be removed independently. That single architectural difference generates almost every row in the table. ## How damage presents, which is the whole decision On aluminum, the impact is the damage. A rock strike dents the sheet and possibly tears a fastener hole. The dent has a boundary you can feel with a straight edge, the stud behind it either moved or did not, and nothing propagates. Two years later the dent is exactly the same size. That predictability is why insurers and shops both find aluminum easier to scope from photographs. On a laminated wall the impact breaks a bond, and the bond keeps failing along the glue line afterward, driven by heat cycling and by the panel flexing every time you tow. The visible ripple is the last stage, not the first. This is why every laminated wall gets sounded before a number is written, and why an estimate from photographs on a laminated unit is close to a guess. ## Where the cost curves cross Below roughly a dinner plate of damage the two are comparable. A small aluminum dent pulls and fills in a few hours; a small bounded laminated release injects and presses in a few more. Above that, the curves separate fast. Aluminum scales linearly, because a bigger repair means a bigger sheet section and one more batten. Laminated repair scales in a step: the moment the release crosses a cutout or the core is wet, you are in a reskin and the number jumps. This is also where refinishing enters. Aluminum panels are flat, so a blend lands cleanly and the break can sit under a batten. Laminated panels are curved and unbroken, so a blend has to travel to the nearest moulding or body line, which on some coaches is the whole side. Paint supplies bill at $55 per paint hour on either construction, but the paint hours are not the same. ## Which construction you actually want to own If you keep a unit for fifteen years, park it covered or in shade, and reseal on a schedule, laminated construction rewards you. It is quieter on the freeway, warmer in the eastern Sierra, and it holds a gloss finish that aluminum never had. The failure mode is slow and it is largely a maintenance function, which means an owner who watches roof seams and window returns can keep it healthy. If you buy used units, tow frequently, store outdoors in full sun, or simply want repair costs that behave predictably, aluminum construction is the cheaper vehicle to own. Nothing propagates, parts are commodity, and a shop can quote it accurately from a photograph. Owners of Airstream and other riveted aluminum trailers sit in a third category, where panel replacement is straightforward but the rivet lines and polished skin add their own labor. ## How the two behave inside a claim Aluminum claims settle faster because the damage boundary is undisputed. An adjuster sees a dent, the shop scopes a section, and there is little room for disagreement. Laminated claims stall more often, and they stall in a predictable place: the initial estimate covered the visible ripple, teardown found release across a much larger area, and the supplement now needs evidence that the release came from the covered impact rather than from age. That is why the sounding record is made before anything comes off, with a tape in frame, dated. Deterioration is not a covered loss on either construction, and the only thing that separates impact driven release from age driven release is documentation written at the right moment. We do that as standard practice and hand the file to the carrier to classify. ## Questions and answers ### How do I tell which wall construction my trailer has? Look at the exterior surface. Vertical battens every few feet with visible fastener heads means aluminum sheet over a frame. A smooth continuous surface with a gloss gelcoat finish and no battens means a laminated wall. Corrugated aluminum with a pebbled texture is the older stick built style, also mechanically fastened and repaired the same way. ### Is an Azdel inner face worth paying more for? For long term ownership, yes. Azdel is a composite that does not wick water or grow mould the way lauan plywood does, so a leak that would have written off a lauan wall often leaves an Azdel wall repairable. It does not prevent bond failure, and it does not make a wall waterproof, but it changes the outcome after a leak. ### Can one unit have both constructions? Frequently. Many towables use laminated sidewalls with an aluminum skinned front wall, or laminated main walls with a stick built rear. Slide room boxes often differ from the walls they sit in. We check each surface separately at intake, because assuming one construction across a whole unit is how a scope goes wrong. ### Does a reskinned laminated panel hold as well as the original? It can, provided the edge bond is reestablished properly and the core is dry and continuous behind it. What fails is a repair that bonded new skin to compressed foam or to a corroded cage member. That is why core condition is part of the scope rather than an afterthought, and why we photograph the cage before the new skin goes on. --- Source: [OCRV Center](https://ocrv.me/comparisons/fiberglass-vs-aluminum-sidewall/). Last verified 2026-07-29.