# Hail Dents The Roof And Bruises The Deck Hail heavy enough to mark an RV membrane also compresses the wood decking under it, and compressed decking does not spring back. What you get is a field of shallow dishes that hold water at every impact, so the sealant around them fails long before the membrane does. ## One strike, two materials, two different injuries An RV roof is a stack, not a surface. Thin membrane, adhesive, a layer of luan or plywood decking, rafters, insulation, and a ceiling panel underneath. A hailstone does not strike the membrane, it strikes the stack, and the energy goes through the sheet into the wood behind it. Both materials respond, and they respond in completely different ways. The membrane is an elastomer, so up to a point it deforms and recovers. Past that point it deforms and stays deformed, with its internal structure broken but no hole in it. The decking is a cellular material and does not recover at all. It crushes. So a single impact produces two injuries: one in a material that is visible and one in a material nobody will look at until the sheet comes off. Only the visible one gets discussed after a storm. ## Why a compressed decking cell never comes back Wood is a structure of cell walls, and a hailstone crushes those walls in a shallow cone under the impact point. Nothing about that is elastic. The fibres have folded, and a folded cell wall does not stand back up when the load is removed. What is left is a locally thinner, locally softer patch of decking with the same fasteners around it holding the same original dimensions. Moisture finishes the job. A crushed area that later takes water swells irregularly rather than uniformly, because the damaged cells absorb differently from the sound ones next to them. Even after it dries, the stiffness does not come back. So the roof now has a permanent surface topography: dished between fixed points, with the fixed points being every fastener and every flange that never moved. ## Standing water at every impact site is the damage that bills Each of those dishes holds a shallow puddle. After rain, obviously, but far more often after a marine layer morning, which is most mornings of the year in this county. Standing water is the single hardest condition a sealant bead faces, and the dishes are frequently right at flange perimeters where the sealant is already working at the limit of what it was designed for. So the sequence runs long. Storm. Then a field of dishes nobody can see. Then a year of standing water working the nearest beads. Then a leak, nine to eighteen months after a storm that has entirely dropped out of the conversation. The roof that passed a walk with no leak and no soft spots is the roof that leaks next winter, and by then the owner has no reason to connect the two events at all. That gap is the reason hail is worth treating differently from other roof damage. Most roof problems announce themselves near the time they start. Hail damage announces itself after the claim has closed. ## The impression pattern in the wood, matched to the map above it When a hail membrane comes off, the pattern is in the decking, and it is more legible in the wood than it ever was in the rubber. Dish for dish, in the same positions, with the same directional bias toward whichever side of the coach faced the storm. Nothing about that is a surprise once you have seen it, and it is the corroborating evidence for everything that was documented from above before the sheet was touched. On a moulded fiberglass roof the same energy goes somewhere else. There is no separate decking layer taking the crush, so the laminate takes it, and what shows is a bruise in the gelcoat with delamination spreading around it in a boundary considerably larger than the visible mark. That is a structural repair rather than a resurfacing one, which is why an identical storm produces a very different estimate on two coaches parked side by side. ## Damage nobody has looked at is not on the estimate An estimate is written on what has been observed, and at the moment a hail estimate gets written nobody has removed a membrane. So the decking is absent from the first number, not because anybody is being difficult, but because it is genuinely unknown. That is a normal and honest position for both a shop and a carrier to be in, and it has a predictable consequence: a hail claim written from above needs a supplement if the sheet comes off. The version that costs an owner real money is the one where the sheet never comes off. Scattered impacts on a young membrane get the plastic replaced and the roof resealed, the claim closes, and the compressed decking is simply never paid for by anybody. Three years later it presents as an unrelated roof job, out of pocket, with no connection to a storm that has long since been settled. That is a cost transfer worth naming out loud rather than discovering. ## What to ask for before authorising anything on a hail claim Four requests, all of them reasonable, none of them adversarial. Ask that the estimate state a teardown point in writing, so a growing number is an expected step rather than an argument. Ask that decking condition be photographed at teardown whether or not it turns out to be damaged. Confirm whether the policy is treating this as comprehensive rather than collision, since that changes the deductible you owe. And get the depreciation and betterment position in front of you before you sign, not at pickup. The last piece of advice is the one that earns nothing. On a genuinely borderline hail roof, with light scattered marking, a young membrane and no leak, the honest recommendation is sometimes to document it thoroughly, keep the file, and watch it for a year rather than opening it now. That is a recommendation to spend no money at this shop today. It is also, on some coaches, the right call, and an owner is entitled to hear it before the alternative. ## What the roof does in the twelve months after a hail settlement A settled hail claim is not the end of the story on a membrane that took compression without splitting. Bruised areas hold water fractionally longer than the sheet around them, and each cycle of standing water, summer heat and overnight cooling works the same spots. What was a survey note in March is frequently a soft patch by the following winter, and by then the claim is closed and the money is spent. That is the argument for documenting thoroughly even on a roof nobody is repairing yet. Photographs of every marked area, dated, with a scale reference, cost nothing on the day and are the only evidence that the damage predates a later loss. Owners who skip that step and come back eighteen months later with a leak are asking a carrier to accept that a hail event they already settled caused something new, which is a much harder conversation than the original one. Reinspection at six months is the cheap half of this. Walk the roof, look specifically at the areas that were marked, and check whether water is still sitting where it sat before. A bruise that has started to hold a puddle is a different object from a bruise that dried out, and telling them apart takes a dry morning and twenty minutes rather than a technician. ## Related - [/services/roof-slide-awning/hail-damage-roof-repair/](https://ocrv.guru/services/roof-slide-awning/hail-damage-roof-repair/) - [/insurance-help/supplements/](https://ocrv.guru/insurance-help/supplements/) - [/insurance-help/deductible-and-depreciation/](https://ocrv.guru/insurance-help/deductible-and-depreciation/) --- Source: https://ocrv.guru/blog/roof-and-water/hail-dents-the-roof-and-bruises-the-deck/ OCRV Center, 23281 La Palma Ave, Yorba Linda, CA 92887. (949) 799-3387. Serving Laguna Niguel, California. All work performed in shop. No mobile or roadside service. Licences: California Bureau of Automotive Repair ARD00288521; EPA CAL000367879. Published ranges are ranges, not quotes. Every figure traces to https://ocrv.guru/prices/.