Dicor lap sealant vs the alternatives
Dicor's lap sealant is the default for membrane roofs; Dicor calls it one of the highest-volume products sold in RV stores. The alternatives aren't better or worse in general. They solve different jobs.
| Product | Maker says it bonds to | Best job | Maker says avoid |
|---|---|---|---|
| Dicor Self-Leveling Lap SealantDicor Products | EPDM, TPO, PVC; also aluminum, wood, vinyl, galvanized metal, fiberglass | Roof edges, vents, vent pipes, screw heads (flat) | — |
| Dicor Non-Leveling (Non-Sag) Lap SealantDicor Products | EPDM, TPO, PVC; same substrates as above | Roof edges, termination rails (vertical) | — |
| Geocel Pro Flex RV Flexible SealantGeocel (Sherwin-Williams) | Aluminum, fiberglass, wood, vinyl, glass, coated steel | Sidewall seams, trim, moldings, vents, tail lights | EPDM, TPO, traffic surfaces |
| EternaBond RoofSeal tapeEternaBond / H.B. Fuller | EPDM, TPO, Hypalon, aluminum, galvanized steel, wood, fiberglass | Seams, tears, skylights (tape) | Silicone-treated surfaces |
| Sashco Through the Roof!Sashco | Metal RV roof, flashing, vent pipes, skylights | Metal roofs, damp-surface leak repair | Rubber membranes such as EPDM; silicone |
| Tough Roof RV CoatingTough Tech Coatings | EPDM, fiberglass, metal, TPO, aluminum, Alpha rubber, wood | Whole-roof recoat | — (follow maker prep) |
Sources: each maker's product page, linked on the cards below. Checked 2026-10-20.
When Dicor is the right call
For an EPDM, TPO or PVC roof, around vents, edges and screw heads, Dicor's self-leveling lap sealant is the purpose-built choice, with non-sag for vertical edges. Dicor also makes a gunnable butyl sealant for the primary seal under windows, vents, skylights and termination rails.
Dicor Self-Leveling Lap Sealant
Edges, vents, vent pipes, screw heads.
- Lists EPDM, TPO and PVC.
- Six colors, 10.3 oz tube.
Spec source: Dicor Products · 501LS series (501LSW white, 501LSB black, 501LSG grey, 501LST tan, 501LSV ivory, 501LSD dove), 10.3 oz tube
Dicor Gunnable Butyl Sealant
Under window, vent and skylight flanges; termination rails.
- Lists TPO, EPDM, PVC, glass, metals, aluminum.
- Dries to a putty-like consistency; grey.
- Dicor coverage: about 11 ft per tube at a 3/8" bead, 24 ft at 1/4".
Spec source: Dicor Products · 451BSG (grey)
When an alternative fits better
Geocel Pro Flex RV Flexible Sealant
Sidewalls, trim and tail lights rather than the roof membrane.
- Paintable; can be applied over itself.
- Adheres to damp surfaces per Geocel.
Not for EPDM or TPO, per Geocel.
Spec source: Geocel (Sherwin-Williams) · 10 oz cartridge; clear, translucent, white, bright white, black, almond (e.g. GC28928 clear)
EternaBond RoofSeal tape
When a joint is long or a tear needs a patch.
- Tape with a UV-stable backing.
- Use EternaPrime below 40°F per the maker.
Spec source: EternaBond / H.B. Fuller · Rolls incl. 2", 4", 6" x 50'; white, black, grey, tan
Sashco Through the Roof!
Metal RV roofs and damp-surface leak repairs.
- Sashco says it sticks to wet surfaces and can seal active leaks.
- Clear, white or black.
Sashco says not to use it on rubber membranes such as EPDM.
Spec source: Sashco · 10.5 oz cartridge; clear, white, black
Tough Roof RV Coating
When the whole membrane is worn, not just the joints.
- Maker states ~50 sq ft per gallon, two coats.
- Sold direct by Tough Tech Coatings.
Spec source: Tough Tech Coatings · Gallon coating and kits (sold direct)