RV roof maintenance and resealing: a practical inspection and resealing routine

Roof, Seals & Leaks · Difficulty: Moderate · Time: Half a day · Updated

Regular inspection is the cheapest RV repair there is. Spend a couple of hours on the roof each spring and fall and you'll catch most leaks before they cause damage.

Recommended tools & parts for this job

Illustration: RV roof cleaner (membrane safe)

Roof, seals & sealants

RV roof cleaner (membrane safe)

Cleans without damaging rubber or TPO roofs.

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Illustration: Self-leveling RV lap sealant (Dicor-style, match your roof type)

Roof, seals & sealants

Self-leveling RV lap sealant (Dicor-style, match your roof type)

For horizontal roof seams, vents and fixtures.

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Illustration: Non-sag RV lap sealant (for vertical surfaces)

Roof, seals & sealants

Non-sag RV lap sealant (for vertical surfaces)

For sidewall fixtures and vertical joints.

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Illustration: Butyl putty tape

Roof, seals & sealants

Butyl putty tape

Bedding seal under windows, vents and trim.

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Illustration: Plastic scraper set

Roof, seals & sealants

Plastic scraper set

Removes old sealant without cutting the roof membrane.

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Illustration: Pin-type moisture meter

Roof, seals & sealants

Pin-type moisture meter

Finds hidden water damage in walls, floors and around windows before it turns to rot.

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Illustration: Rubber seal conditioner

Slide-outs & awnings

Rubber seal conditioner

Keeps slide and door seals supple, especially in dry Alberta air.

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Why roofs fail

RV roofs live a hard life: UV exposure, temperature swings, road vibration that flexes the body, tree branches, hail, and in Alberta, chinook freeze-thaw cycles that can swing temperatures dramatically in a single day. Sealants shrink, crack and pull away over time, and plastic vent covers turn brittle. Most manufacturers recommend inspecting roof seals regularly, often every few months or at least twice a year. Check your RV's manual and warranty terms, because some warranties require documented roof inspections.

Safety: Confirm your roof is walkable and stay on supported areas. Avoid working on wet, frosty or windy days. Use a stable ladder and a spotter. Sealant solvents can be flammable and irritating, so follow product labels and ventilate.

A simple schedule

When What
Spring (after de-winterizing) Full roof inspection and clean, reseal anything cracked
Before a big trip Quick visual from the ladder: vents, A/C, skylight, edges
After hail, high wind or a tree strike Inspect immediately (see RV hail damage in Calgary and Alberta: prevention, inspection and repair)
Fall (before storage) Full inspection and clean, reseal before winter

Take photos each time. Comparing photos over time makes slow deterioration obvious, and they help with insurance claims.

Step 1: Clean

Use a cleaner made for your roof type and a soft brush. Avoid petroleum-based, citrus or abrasive cleaners unless the roof manufacturer approves them, as some damage EPDM and TPO membranes. Rinse thoroughly and keep runoff off the sides as much as you can, because chalky EPDM residue streaks paint.

Step 2: Inspect every seal

Work in a pattern, front to back. Check:

  • Around each vent, fan, skylight, antenna, A/C unit, plumbing vent and cable entry.
  • Along the front and rear cap seams and the edge trim.
  • Screw heads that aren't fully covered.
  • The membrane itself: tears, punctures, bubbles, loose sections, soft spots underfoot.
  • Plastic parts: vent lids and frames, skylight domes. Check for chalkiness, cracking or hail dings.

Signs that sealant needs attention: cracks, gaps between the sealant and the surface, missing sections, or sealant that has gone hard and brittle. Light surface checking ("alligatoring") on otherwise well-bonded sealant is common. Many owners add a fresh, compatible layer over it.

Step 3: Choose the right sealant

  • Horizontal surfaces (roof): self-leveling lap sealant compatible with your membrane. It flows to seal edges and screw heads.
  • Vertical surfaces (walls, end caps): non-sag sealant that stays put.
  • Under fixtures and window frames: butyl putty tape as a gasket.
  • Don't use household silicone on RV roofs unless the manufacturer specifies it. Most other sealants won't stick to silicone residue later, which makes future repairs harder.

Step 4: Reseal

  1. Remove loose or failed sealant with a plastic scraper. Leave well-bonded sealant if the new product is compatible.
  2. Clean with the solvent or cleaner the sealant manufacturer recommends.
  3. Apply a continuous bead that covers the joint and extends onto both surfaces. Self-leveling sealant will spread.
  4. Cover every screw head.
  5. Let it cure according to the product label. Watch for minimum application temperatures and rain-free cure times, which matter in Alberta's spring and fall.

Windows and side fixtures

Window leaks usually come from dried-out butyl behind the frame. Running sealant around the outside can buy time, but the proper fix is to remove the window, clean off the old butyl, apply new butyl tape and reinstall, tightening screws evenly without crushing the butyl flat. It's a manageable job for a careful DIYer with a helper. Have the interior trim ring and screws ready.

Roof coatings

Some owners apply a roof coating to older EPDM or fibreglass roofs. Coatings can extend life when they're properly matched to the membrane and the surface is well prepared, but they aren't a fix for soft decking or major tears. Check with the RV or membrane manufacturer before coating, because it may affect warranty.

Seals elsewhere

  • Slide seals and door seals: Clean them and apply a rubber seal conditioner. Alberta's dry air ages rubber faster.
  • Compartment doors: Check that gaskets compress evenly.
  • Clearance lights: Small lights on the roof edges and caps often leak. Reseal or use butyl under them.

Winter considerations

Snow load on RV roofs can be significant after a heavy, wet storm. If you store outdoors, check the manufacturer's guidance on snow removal and use a soft roof rake or broom from a safe position. Never use metal shovels or scrape down to the membrane. Ice dams around vents are worth watching during chinook melt cycles. See RV storage tips for Calgary winters.

When to call a pro

Membrane replacement, soft or delaminated decking, extensive hail damage, or any job where you can't work safely at height.

How-to videos

How to Apply Dicor Lap Sealant | RV Roof Sealant Application Tips by Dicor (YouTube)
How to Install and Seal an RV Roof Vent | Dicor Lap Sealant Application by Dicor (YouTube)

Videos are made by third-party creators and load from youtube-nocookie.com only when you press play. Models differ, so always follow your own manuals and the safety notes on this page.

Disclaimer: This guide is general information based on common RV designs. Models differ, so check your owner's manual and appliance manuals. Propane, 120V electrical and brake systems can cause serious injury if handled incorrectly. If you are unsure, stop and book a certified RV technician.