Roof Coatings & Membranes

Coating vs. replacing your RV roof

The first decision is whether you're coating or replacing. If the membrane is sound but chalking, fading, or showing surface age, a coating restores it for a fraction of the cost and effort of a tear-off. If the membrane is cracked through, blistered, or water's already getting past it in spots, a coating just buys a little time — that roof wants a new membrane.

• Match the product to your roof type. This is the one that trips people up. EPDM rubber, TPO, fiberglass, and metal all take different coatings. The Dicor Signature EPDM coating and EPDM adhesive are for rubber roofs; the Dicor acrylic elastomeric is formulated for metal; and the Dicor fiberglass clean-and-prep is for fiberglass. Using the wrong chemistry means poor adhesion and early failure.
• Elastomeric coatings. Products like the Heng's elastomeric and Dicor coatings stay flexible so they move with the roof instead of cracking, and they're reflective to knock down heat and UV. Coverage is rated per gallon — measure your roof and buy enough to hit the recommended thickness in the coats specified.
• Membrane replacement. When you're replacing, the Dicor TF95W PVC system and Lasalle Bristol XTRM-PLY and Xtrm PVC rolls come in RV-width sheets (9.5 feet) cut to your rig's length. PVC and EPDM install differently, so plan the whole system — membrane plus the right adhesive.
• Adhesive and prep. A membrane needs the matched adhesive, like the Dicor water-based EPDM adhesive, and every coating needs a clean, prepped surface first. The Dicor clean-and-prep does the surface work — skip it and even the best coating peels.

This is the biggest job on the roof, so plan for weather: coatings and adhesives need a dry window and a temperature range to cure. Before you commit to a full coat, walk the roof and reseal any bad seams and penetrations with lap sealant — and for ongoing EPDM upkeep between coatings, the products in rubber roof care keep the membrane conditioned.