Thirty One Feet of Hail Damage and a Roof That Stayed

The conversation opened with a decision already made: the roof needs replacing, how soon can you do it. That assumption is the reason this write up exists, and it is wrong often enough to be worth walking through. This account is a composite drawn from several hail files at OCRV Center rather than one specific job.

The coach was thirty one feet, laminated construction, a one piece EPDM membrane over a luan and foam deck, aluminum sheet on both sidewalls and across the roof to sidewall transition panels, fiberglass front and rear caps. It had been parked outside during a hail event and the owner had climbed up afterward, seen a field of shallow dimples across the membrane, and concluded the roof was finished.

What the owner had actually seen was hail bruising, which is a real condition and a different one from a breach. A membrane can look thoroughly beaten and still be watertight, and a membrane can look nearly untouched and have three punctures where a stone caught a seam edge. Neither of those is visible from a quick look from a ladder.

The other thing that had not been looked at yet was everything below the roofline. Hail rarely falls straight down. It comes in at an angle with the wind behind it, which means a long flat aluminum sidewall takes a lot of impacts at a shallow angle. In this case that was where most of the money was, and nobody had walked the sides yet. Hail specific work is scoped on the hail damage roof repair page.

Mapping a hail struck membrane means walking the entire roof on a grid and marking every finding, not scanning it and forming an impression. It takes a couple of hours on a coach this size and it is the step that decides everything downstream.

The roof gets washed first, because dirt hides both dimples and cuts. Then it is divided into sections, front cap to first vent, vent to air conditioner, and so on, and each section is walked at a low angle with the light behind so the surface texture reads. Findings are marked in chalk in two categories: bruise and breach. Every marked point gets a photograph with a scale reference in frame.

Then the seams. Hail damage on a membrane roof concentrates at edges, because that is where the material is bonded, lapped or terminated and where a stone has something to catch. Every perimeter termination bar, every vent flange, every seam over a roof to sidewall transition and every sealant bead around a penetration gets examined by hand. Sealant that has been struck often shows a hairline separation from the flange that will not be visible from standing height.

Finally the deck underneath. Walking the roof slowly and deliberately tells you a great deal about what is under the membrane. A soft or spongy area means the substrate is compromised, and that changes the job entirely regardless of what the membrane looks like. In this case the deck was uniformly firm from cap to cap, which is the finding that made everything that followed possible.

A bruise is compression damage. A puncture is a breach. They look similar from a ladder and they mean completely different things for the repair.

EPDM is a flexible rubber sheet, and when a hailstone hits it the membrane deflects into the substrate below and compresses. What is left is a shallow dimple where the material has been permanently deformed and, in the worst cases, where the surface has lost some of its protective top layer. The sheet is still continuous. Water still runs across it and off the edge. The membrane has lost some of its ultraviolet protection and some of its thickness at that point, which shortens its remaining life, but it has not failed.

A puncture is different. The sheet is open, or a seam has separated, or a sealant bead around a penetration has pulled away enough to admit water. That is an active leak path into a luan and foam substrate that will delaminate and rot, and it is not a wait and see item. Punctures cluster near hard edges: the corner of a skylight flange, the lip of a vent, the termination bar along the roof edge, and anywhere a previous repair left a raised bead for a stone to catch.

The practical distinction is what the two repairs cost. Bruised but continuous membrane is treated with cleaning, priming and a coating system that restores ultraviolet protection and adds film thickness. Punctures are cut out and patched with compatible material, or if there are enough of them in one area, that section is replaced. Full membrane replacement becomes the answer when the substrate is wet or the punctures are too numerous to patch sensibly. Membrane construction is covered further under rubber roof repair.

The real damage was in the components that stand above the roof plane and in the aluminum. Hail does not damage a flexible membrane the way it damages a rigid plastic shroud, and this coach demonstrated the difference clearly.

Both air conditioner shrouds were cracked. Shrouds are thin thermoplastic, they sit higher than everything else on the roof, they are unsupported across their span and they have usually spent years in the sun losing impact resistance. A hailstone that leaves a dimple in EPDM will crack a sun aged shroud outright. Neither shroud on this unit was serviceable, and a cracked shroud is not cosmetic: it admits water into the condenser section and lets it track down through the roof opening.

Three vent lids were broken and one was gone. Vent lids are acrylic or polypropylene, thin, and hinged at one edge, so an impact near the open edge levers the whole lid against the hinge. A vent with a missing lid is an open hole in the roof, which is the most urgent finding on the list regardless of how the membrane looks.

Then the aluminum. Both sidewalls and the roof to sidewall transition panels showed a dense field of shallow dents on the side that faced the storm, thinning out toward the leeward side. Aluminum sheet over a laminated wall does not spring back the way it does over an open frame, because the adhesive bond behind it resists the metal returning to shape. Those dents were permanent. Roof vent work runs $250 to $1,200 and air conditioner service runs $750 to $4,500 depending on what the impact reached.

The sidewalls mattered more because they were the larger, more expensive and more visible problem, and because their damage was structural to the laminate in a way the roof bruising was not.

A laminated sidewall is a stack: outer aluminum or fiberglass skin, adhesive, luan substrate, block foam or aluminum framing, interior panel. It is bonded as a unit under pressure, and its stiffness comes from that bond. When a hailstone dents the outer skin hard enough, the skin deforms but the adhesive layer behind it does not stretch equally, and the bond at that point can break. You now have a dent with a small delaminated zone behind it.

One of those is nothing. A field of two hundred of them across a long wall is a wall that has lost stiffness, and over time the individual delaminated spots grow and connect. That progression is slow and completely invisible until the day the skin starts to ripple. Which is why the sidewalls, not the roof, drove this estimate.

Assessment on aluminum over laminate is done by tapping. A sound bonded panel gives a tight, high note. A delaminated area gives a dull, hollow one, and the boundary between the two is audible within about an inch. The whole wall gets tapped on a grid and the hollow zones are outlined. Aluminum skin work runs $2,500 to $25,000 and delamination repair runs $1,500 to $20,000, and where a job lands in those bands is decided by how much of the wall taps hollow, not by how many dents you can count. Dent work generally is covered under dent removal and repair.

The arithmetic came out in favor of a recoat because the membrane was continuous, the deck was firm, and the punctures were few enough to patch. Once those three conditions hold, replacing the membrane is spending money to solve a problem that has already been solved.

A roof recoat is not paint. The membrane is cleaned and rinsed thoroughly, all failed sealant is removed and every penetration is resealed, individual punctures are patched with compatible material, a primer appropriate to EPDM is applied, and then a coating system is built up in coats with reinforcing fabric bedded in at seams and around penetrations. Done properly it restores ultraviolet protection, adds film thickness over the bruised areas and reseals every termination.

A membrane replacement removes everything: air conditioners, vents, skylights, the roof rack, the perimeter trim and the old membrane, then inspects and repairs the deck, bonds new material, and reinstalls all of it with fresh sealant. It is the right answer when the deck is wet or soft, when the membrane has separated from the substrate over a large area, or when punctures are numerous enough that patching becomes a patchwork.

Path	Posted band	What it covers	When it is correct
Roof recoat	$750 to $4,500	Clean, patch, reseal penetrations, prime, build coating with reinforcement at seams	Membrane continuous, deck firm, punctures countable and patchable
Roof membrane replacement	$3,500 to $18,000	Full removal of rooftop components, deck inspection and repair, new membrane, full reseal	Wet or soft deck, widespread separation, punctures too numerous to patch

On this composite the recoat plus vent lids, shrouds, sidewall panel work and refinish came in well under what a membrane replacement plus the same sidewall work would have cost, and the sidewall work was required either way. Both bands are on the posted rate sheet.

Sometimes the correct call is the full membrane replacement, and pushing a recoat in those cases is how a shop turns one job into two. Four findings send it that direction.

A soft deck is the first and it is absolute. If the substrate under the membrane is wet, the luan is already delaminating and the foam is holding water. Coating over that seals the moisture in and accelerates the rot. The membrane has to come off so the deck can be opened, dried, and repaired or replaced.

Widespread separation is the second. If the membrane has lifted from the deck over a large area, whether from age, a previous coating that trapped moisture or adhesive failure, then any coating goes onto a surface that is moving independently and will crack. Tapping and walking the roof finds this quickly.

Puncture count is the third. There is no fixed number, but when patches start to overlap or a section has more patch than membrane, replacement of that section or the whole roof becomes cheaper and better. And the fourth is age combined with previous coatings. A membrane that has already been coated twice, has lost thickness and is at the end of its service life is not worth another coating cycle; the labor to prep it approaches the labor to replace it.

Insurance also affects the framing of this. Adjusters generally fund the repair that restores the vehicle to its pre loss condition, and where a recoat does that, that is what gets written. Where the deck is compromised, documented photographs and moisture readings support the larger scope. The distinction is worth reading about on repair versus replace, and full replacement scope sits under full roof replacement.

Bring photographs taken as soon after the event as possible, your policy declarations page, and the claim number if one has been opened. Photographs matter because hail bruising in a membrane becomes less visible as the surface weathers, and an adjuster looking at the roof weeks later may see less than was there.

Ask for the roof to be mapped rather than assessed. A mapped roof produces a marked, photographed grid with bruises and breaches counted separately, seam and penetration findings listed, and a note on deck condition from walking it. That document is what supports a scope of work with an adjuster, and it is also what tells you honestly whether you are in recoat territory or replacement territory.

Ask specifically about the sidewalls, because that is the part owners consistently overlook and it is frequently the larger number. A tap test on a grid across both walls, with hollow zones outlined and photographed, belongs in the same document as the roof map.

On what it costs: a collision estimate carries no charge, and there is no charge for insurance walk ins. Body and paint labor is posted at $210 per hour with paint supplies auto calculated at $55 per paint hour. Roof recoat runs $750 to $4,500, roof membrane replacement runs $3,500 to $18,000, aluminum skin work runs $2,500 to $25,000, roof vent work runs $250 to $1,200 and air conditioner service runs $750 to $4,500. Bring the coach in with the vent lids covered if any are missing, and start at the contact page. Other teardown write ups sit under before and after stories.