Best RV sealant by job
Start with the job, not the brand. The single biggest mistake is putting a sealant on a roof membrane its maker says it won't bond to.
| Job | Pick and why | Price |
|---|---|---|
| Roof edges, vents, vent pipes, screw heads on EPDM, TPO or PVC (flat, horizontal) | Dicor Self-Leveling Lap SealantSelf-leveling: flows out to seal horizontal joints. Dicor lists it as compatible with EPDM, TPO and PVC membranes. | Check price |
| Front/rear roof edges, termination rails, anything vertical or sloped | Dicor Non-Leveling (Non-Sag) Lap SealantNon-sag version of the same lap sealant, made for vertical surfaces so it does not run. | Check price |
| Under window, vent, skylight flanges and termination rails (primary seal) | Dicor Gunnable Butyl SealantGunnable butyl dries putty-like for a seal between lapping parts. Dicor lists TPO, EPDM, PVC, glass, metals and aluminum. | Check price |
| Fiberglass and aluminum seams, trim, moldings, tail lights, window frames (sidewalls) | Geocel Pro Flex RV Flexible SealantFlexible, paintable joint sealant for aluminum, fiberglass, wood and vinyl. Geocel says do not use on EPDM or TPO. | Check price |
| Long roof seams, tears and patch repairs on EPDM, TPO, fiberglass or aluminum | EternaBond RoofSeal tapeTape, not caulk. Bonds to EPDM, TPO, Hypalon, aluminum and fiberglass; not for silicone-treated surfaces. | Check price |
| Metal RV roofs, flashing and penetrations, including damp surfaces | Sashco Through the Roof!Sashco lists metal RV roofs and says it sticks to wet surfaces. Sashco says not to use it on rubber membranes such as EPDM. | Check price |
| Whole-roof recoat (aging EPDM, TPO, fiberglass, metal, Alpha rubber) | Tough Roof RV CoatingA brush/roll liquid rubber coating rather than a caulk; maker states ~50 sq ft per gallon, two coats. | View at maker |
Compatibility notes come from each manufacturer's product page (linked on every product card). We don't list prices because they change; use "Check price" for the current one.
Self-leveling vs non-sag lap sealant
Self-leveling
Flows and levels itself, so it fills around vent flanges, screw heads and flat roof edges. On a vertical or steep surface it will run. Example: Dicor 501LS series.
Non-sag (non-leveling)
Holds its bead where you put it. Use it on front and rear caps, termination rails and anything that isn't flat. Example: Dicor 551LS series.
Top picks
Dicor Self-Leveling Lap Sealant
Roof edges, air vents, vent pipes and screw heads.
- Compatible with EPDM, TPO and PVC membranes; also bonds to aluminum, wood, vinyl, galvanized metal and fiberglass (per Dicor).
- Dicor cure guide at 50–70°F: skins in about 5 minutes, waterproof in about 4 hours, 80% cured at 48 hours, fully cured at 30 days.
- In cold weather, Dicor says to warm the tube to room temperature first.
Spec source: Dicor Products · 501LS series (501LSW white, 501LSB black, 501LSG grey, 501LST tan, 501LSV ivory, 501LSD dove), 10.3 oz tube
Dicor Non-Leveling (Non-Sag) Lap Sealant
Roof edges and termination rails where a self-leveling bead would run.
- Same membrane compatibility as the self-leveling version (EPDM, TPO, PVC) per Dicor.
- Made for vertical surfaces.
- Same colors as the self-leveling line, so you can match your roof.
Spec source: Dicor Products · 551LS series (551LSW white, 551LSB black, 551LSG grey, 551LST tan, 551LSV ivory, 551LSD dove), 10.3 oz tube
Geocel Pro Flex RV Flexible Sealant
Seams, trim, moldings, vents and tail lights on the body of the RV.
- Bonds to aluminum, fiberglass, wood, vinyl, glass and coated steel; Geocel says it adheres even to damp surfaces.
- Paintable and can be applied over itself.
- Not for traffic surfaces.
Geocel says not to use Pro Flex RV on EPDM or TPO. For rubber roofs, use a lap sealant made for membranes.
Spec source: Geocel (Sherwin-Williams) · 10 oz cartridge; clear, translucent, white, bright white, black, almond (e.g. GC28928 clear)
EternaBond RoofSeal tape
Long seams, tears and patches where a tape beats a caulk bead.
- Bonds to EPDM, TPO, Hypalon, aluminum, galvanized steel, wood and fiberglass (per H.B. Fuller).
- Apply between 40°F and 150°F; below 40°F the maker says to use EternaPrime primer.
- Not recommended on silicone-treated surfaces.
Spec source: EternaBond / H.B. Fuller · Rolls incl. 2", 4", 6" x 50'; white, black, grey, tan
Before you buy: three quick checks
- Know your roof. EPDM (rubber), TPO, fiberglass, aluminum/metal or a coated roof. Your owner's manual or the RV maker can tell you. See sealant by roof type.
- Check for silicone. Several makers (including EternaBond and RV Roof Magic) say their product won't bond over silicone. Old silicone has to come off first.
- Match the old sealant. If you are touching up, stay with a product that is compatible with what's already there, or remove the old bead down to a clean surface.