RV Roof Coatings

RV roof coatings are liquid-applied coatings used to protect, restore or seal the roofs of recreational vehicles, including motorhomes, travel trailers, fifth wheels, campers and toy haulers. RV roofs face sun, rain, hail, tree branches, flexing on the road and temperature swings, and they contain many seams and penetrations. Over time, factory membranes chalk, shrink, crack and leak. A properly selected and applied coating can seal minor defects, improve reflectivity and extend roof life. RV roof coating is a specialized branch of roof coatings.

RV roof types

EPDM rubber

A common factory roof material, usually white or black. EPDM chalks and oxidizes with age. Many EPDM roofs are thin and glued to a wood deck.

TPO

A thermoplastic membrane similar to commercial TPO roofing. Its smooth, low-energy surface needs specific cleaning and primers (see coating single-ply roof membranes).

Fiberglass

Molded fiberglass roofs are rigid and durable but can crack and fade (see coating fiberglass (FRP)).

Aluminum

Older trailers and some campers have aluminum roofs with riveted seams (see coating aluminum).

Previously coated roofs

Many roofs carry earlier coatings, which must be evaluated for adhesion and compatibility (see coating existing coatings).

Coating chemistries

• Acrylic elastomeric coatings. Waterborne, reflective, often brush or roll applied by owners (see elastomeric coatings).
• Silicone coatings. Tolerate ponding and weathering well; later recoats usually must be silicone (see silicone coatings).
• Liquid EPDM and rubber coatings. Formulated for rubber roofs.
• Aluminum-pigmented coatings. Aluminum flake reflects sunlight and forms a protective leafing layer.
• Polyurethane and polyurea systems. Spray-applied or brushable systems that cure into a tough, seamless membrane with high resistance to impact and abrasion.

Basecoat and topcoat systems versus single-coat systems

Some RV roof products are single-coat, standalone systems. Others are designed as a basecoat with a specific topcoat. Mixing these up can cause problems, so the manufacturer’s system instructions matter.

ArmorThane’s RV roof line illustrates the range. It includes ArmorSeal 100 AL, an aluminum-pigmented coating; SureGrip, a basecoat that is topcoated with ArmorDeck; and ArmorFlex UV, an aliphatic coating sprayed as a standalone system without a topcoat. ArmorFlex UV is not sprayed over SureGrip, because each is designed for its own system. More detail is available on ArmorThane’s RV roof coatings page. Other manufacturers have their own system rules, which should be followed in the same way.

Assessment

Before coating, inspect for:

1. Soft or delaminated decking. Water damage under the membrane must be repaired first; coatings do not fix rotten decks.
2. Leaks at vents, skylights, air conditioners, antennas, ladders and edges.
3. Sealant condition. Self-leveling lap sealants and caulks crack and shrink with age.
4. Membrane condition. Tears, shrinkage, loose edges and seams.
5. Existing coating adhesion, tested with tape or knife tests (see adhesion testing).

Preparation

• Wash the roof with cleaners recommended for the membrane and coating. Remove chalk, dirt, oils and biological growth.
• Rinse and allow to dry completely.
• Remove failed sealant and reseal with compatible products.
• Repair tears and seams with compatible tapes or patches.
• Reinforce seams, edges and penetrations with fabric or tape embedded in coating where the system calls for it.
• Prime if required by the membrane and coating.
• Mask sidewalls, windows and accessories, and protect vehicle paint from overspray.

Application

• Apply within the temperature and humidity range on the data sheet (see environmental conditions for coating).
• Use the specified method: brush, roll, airless or plural-component spray.
• Build to the specified thickness in the required number of coats, checking with a wet film gauge (see wet film thickness measurement).
• Detail around penetrations first, then coat the field.
• Allow cure before rain, dew or travel, as directed.

Safety

• RV roofs are slippery and may not support full body weight everywhere. Walk on supported areas, use ladders safely, and use fall protection where needed (see fall protection for painters).
• Spray-applied polyurea and polyurethane require trained applicators and respiratory protection.
• Ventilate the RV interior if roof vents are open during work.

Maintenance

• Inspect the roof at least twice a year and after storms or branch strikes.
• Clean with mild cleaners approved by the coating manufacturer.
• Check sealants around fixtures.
• Recoat or repair according to the manufacturer’s guidance.
• Use covers or covered storage where available.

In practice

In practice, RV owners usually start by inspecting the roof for soft spots, failed sealant and damaged seams. Any water damage under the membrane should be repaired first. The roof is then cleaned, and the coating chosen to suit the roof material and the owner’s use. Options include ArmorSeal 100 AL, SureGrip for walkable areas, and ArmorFlex UV, among others; the right choice depends on the roof type and preparation. Regular inspection of seams and fixtures after coating helps the roof stay watertight.

Key terms

• EPDM roof. A rubber roof membrane common on RVs.
• TPO roof. A thermoplastic RV roof membrane.
• Fiberglass roof. A molded or laminated roof surface used on some RVs.
• Lap sealant. Self-leveling sealant around vents, edges and fixtures.
• Reflectivity. The ability of a light-colored coating to reflect sunlight and help reduce roof temperature.

Frequently asked questions

Can I coat a new RV roof?

Usually it is not necessary while the factory roof is sound and under warranty. Check the RV and membrane warranty before coating.

Can I put any coating over EPDM?

No. Choose coatings and primers approved for EPDM and test adhesion.

Will a coating stop leaks?

It can seal minor defects. Leaks from failed sealants, fixtures or damaged decks must be repaired first.

Related entries

• Roof coatings
• Elastomeric coatings
• Silicone coatings
• Coating fiberglass (FRP)
• Coating single-ply roof membranes (new)
• Aliphatic vs aromatic coatings (new)