Is Your RV Roof Ready for the Rain? A Pre–El Niño Roof Checkup

By Tim Lavender, Master Certified RV Technician (NRVTA)  ·  Updated August 12, 2026

A real one from a recent job — a 20-plus-year-old RV roof here in the county, oxidized and chalky after years without maintenance. This is what a neglected roof looks like heading into a wet winter.

Forecasters are calling for a strong El Niño this fall, with near-record rainfall possible along the Santa Barbara coast. For your RV, the roof is the one system where a small, ignored problem quietly turns into an expensive one. Water doesn't announce itself — it seeps through a hairline crack in a seal, works into the wood decking, and by the time you see a stain on the ceiling inside, you're often looking at rotted decking and delamination instead of a tube of sealant.

The good news: catching it is straightforward, and much of this is within reach for a hands-on owner. The photos here came off that same rig — cracked, crumbling sealant, a duct-tape "repair," and soft, water-rotted decking hiding under a vent. That roof went years without a look. Yours doesn't have to. Here's how to check it before the first big storm.

1. Get up there safely — and know what you're standing on

First rule: not every RV roof is rated to walk on, and a soft or aging roof can be slick. Use a stable ladder, work only on a dry roof, keep your weight near the strong center line, and stay off the edges — and if you're not steady at height, this is a fine place to stop and let us handle it. While you're up there, identify your membrane. Most RV roofs are a rubber membrane — EPDM (it weathers to a chalky gray and shows a black base layer where it's worn, exactly like the roof above) or TPO (a single white layer); a few are fiberglass or aluminum. Which one you have decides what cleaner and what sealant are safe to use.

2. Inspect every seal and seam — that's where most leaks start

Water almost never comes through the open middle of the roof; it comes in around the things poking through it. Walk the whole perimeter and every penetration: vents, the A/C shroud, skylights, the antenna base, the refrigerator and plumbing vents, and the front and rear seams. Look closely at the lap sealant — the bead of white or black sealant around each fixture — for cracks, gaps, peeling, missing chunks, or exposed screw heads. Cracked, crusty sealant like this is a standing invitation to rainwater.

3. Check the membrane itself

Scan the flat field for tears, punctures, or bubbles. On EPDM, look for worn spots where the black base shows through and for heavy chalking. Then gently feel for soft or spongy spots underfoot — a springy area means water has already gotten in and the decking below may be rotting. Don't dig into it; just note where it is and flag it for a technician. This is what's waiting under a vent that leaked for years:

4. Clean it — gently

Sweep off leaves and debris, then wash with a mild, roof-safe cleaner, a soft or medium brush, and water. On a rubber roof, skip anything petroleum- or citrus-based, harsh solvents, abrasive pads, and pressure washers — they can damage the membrane and blast open your seams. Fresh sealant won't bond over dirt and chalk, so rinse well and let the roof dry completely before you seal anything.

5. Reseal — clean and top-coat, or scrape and redo

Here's the part people overthink: you usually do not need to strip off all the old lap sealant. If the existing sealant is still sound and simply aged, clean it, let it dry, and lay a fresh bead of compatible self-leveling lap sealant right over the top on the horizontal seams (use the non-sag type on vertical surfaces). Only where the sealant is cracked, lifting, or crumbling should you scrape off the loose material first, then clean and re-seal. Two musts: match the sealant to your membrane type — there are EPDM and TPO versions, and the wrong one won't bond — and never substitute hardware-store silicone, spray-on products, or household caulk.

6. Put it on a schedule

Check your seals at least twice a year, and always before the rainy season, after a branch scrapes the roof, or when you buy a used rig. A $10 tube of sealant on a dry afternoon is the cheapest insurance you'll ever buy against a rotted roof. Sealing the roof is part of our roof and exterior services, and it's one of the smartest pre-winter jobs an RV owner can stay ahead of.