RV OWNER’S FIELD GUIDE · ROOF & BODY
TPO vs. EPDM vs. Fiberglass Roofs
Three different materials, three different maintenance routines. Know which one is over your head.
TPO (Thermoplastic Polyolefin)
White, single-ply membrane, common on newer travel trailers. Reflects heat well and is relatively easy to clean, but seams and penetrations are heat-welded or taped and need periodic inspection — a failed seam is a leak point that’s easy to miss visually.
EPDM (Rubber Membrane)
Black or white rubber, older but still common. Needs a specific rubber-roof conditioner — regular RV wash soap or the wrong cleaner can dry it out and accelerate cracking. UV exposure is its main enemy over time; a chalky white residue on a black EPDM roof is a sign it needs conditioning, not necessarily failing.
Fiberglass
Rigid, common on higher-end motorhomes and some trailers. Doesn’t need conditioning like rubber, but gel coat can oxidize and chalk over time, and any cracks in the gel coat are a direct path to water intrusion — unlike a membrane roof, fiberglass doesn’t flex to absorb minor stress.
OUR TOOL KIT
Roof sealants by surface
Dicor 501LSW self-leveling lap sealant — The right sealant for horizontal seams, vents and fixtures on EPDM and TPO roofs.
Sikaflex-221 polyurethane sealant/adhesive (white) — For vertical seams, trim and fiberglass where the bond needs to flex. Not for EPDM or TPO.
EternaBond RoofSeal tape (4 in x 50 ft) — A permanent patch over seams and small tears that bonds to most roof types.
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