RV roof leak: where it is actually coming from and what the repair costs

Almost every RV roof leak in Florida starts in the same place: a joint where the roof is penetrated by something, sealed with lap sealant, then baked by the sun every morning and rained on nearly every summer afternoon. The membrane usually outlives the sealant by many years. That is good news, because resealing runs $500 to $1,200 while a failed membrane with wet decking runs $2,000 to $3,000 or more.

Check this first (fifteen minutes, if the roof is walkable)

Only go up if your roof is rated to be walked on and you are comfortable up there, and never in the afternoon storm window. If not, we will do it as part of the trip fee.

1. Look at every penetration. Roof vents, the rooftop AC, skylights, the refrigerator vent, antennas, solar mounts, and the front and rear caps. Sealant that has gone chalky, shrunk away from the flange, cracked into a crazed pattern, or turned black with mildew along the edge has failed, whatever it looks like from ten feet away.
2. Press with a thumb along the seams. Sealant should still have some give. Hard, brittle, glassy sealant is done.
3. Feel for soft spots as you move around. Anything that flexes underfoot means water has reached the decking, which changes the job.
4. Inside, find the stain and work uphill. Water travels along framing and can surface several feet from where it entered. The nearest penetration uphill of the stain is where to look first. A musty smell with no visible stain is also a leak; in this humidity the mold arrives before the stain does.
5. Check the AC gasket. A rooftop AC seals to the roof with a compressible gasket, not with sealant, and that gasket takes a set over the years. Water around the AC shroud, or dripping from the interior AC ceiling assembly, is nearly always the gasket rather than the roof. On the other hand, drips from the AC assembly on a humid day with no rain are usually condensate, which is a different problem.

What is usually wrong

Those ranges are from the pricing page, on top of the $75 to $150 trip fee and $125 to $190 hourly labor.

Why Florida roofs fail this way

Two things work on a roof here, and they take turns every day. In the morning the sun bakes the sealant, driving out the plasticizers that keep it flexible. In the afternoon, through the wet season, the storm arrives and tests it. Zephyrhills gets its heaviest rain in July, around six inches in a typical year’s July alone, and the muggy stretch runs from May through November. Sealant that was merely cracked in June is a leak by August, and because the rain comes almost daily, the decking underneath never gets a chance to dry out between storms.

The humidity adds a second mechanism a dry climate does not have. Water that reaches the decking or the insulation stays there, and mold grows in it. Owners arriving in November after a summer away sometimes notice the smell before they notice any stain. That is why the arrival inspection matters as much as the spring one.

Then there is the hurricane season, June 1 through November 30 with its peak in early September. Hurricane Milton came ashore on the evening of October 9, 2024, and the Hillsborough River at Zephyrhills crested nearly two feet over its record. A rig parked through that has had its vent covers, antenna mounts, and every seam worked by wind and driven rain, and the right move afterward is an inspection, not an assumption.

What a proper reseal involves

The labor is in the preparation, not the caulk. Failed sealant gets dug out rather than covered, the substrate is cleaned back to a surface new sealant can actually bond to (mildew has to come off too, or the new bead sits on a film), and then the correct product goes on: self-leveling sealant on horizontal surfaces and non-leveling on vertical ones, both matched to your roof material. EPDM, TPO, and fiberglass roofs do not all take the same products, and using the wrong one is how a reseal fails in a year.

Timing matters here. Fresh sealant needs a dry window to cure, and in the wet season that window is the morning. We plan roof work around it.

While the tech is up there, the AC gasket, the vent covers, and the skylight all get looked at, because the trip and the ladder are most of the cost of dealing with any of them.

When the decking is wet

If the roof flexes underfoot or the ceiling panel is spongy, water has been in the structure long enough to reach the wood. That is a bigger conversation, and the honest version of it includes the possibility that the repair is not worth it on an older rig. We will give you that assessment straight rather than selling a reseal over rotten decking. What we will not do is guess: the extent of wet decking is something you find by opening it up, and we say so before starting.

What to expect on the call

Photos of the interior stain and of the nearest roof penetration are worth a lot. Tell us the rig’s age, the roof material if you know it, and whether the leak shows up in rain or all the time. We work on site at park spaces, storage lots, and driveways across Zephyrhills, Dade City, Wesley Chapel, Land O’ Lakes, and Plant City. The roof cost calculator will price a reseal for your rig size right now.