Most RV roof leaks start small: a crack in old sealant, a branch puncture, a tear at a seam. Dicor makes three kinds of fix for these, and they are not interchangeable. This guide sorts out which one fits which damage, using Dicor's product directions, FAQ and roof care handbook.
Pick the fix by the damage
| What you find | Dicor fix |
|---|---|
| Cracked or shrunken sealant around a vent, skylight or edge | Clean it and run a new bead of self-leveling lap sealant (or non-sag on vertical faces) |
| A puncture, tear or break in the membrane | EPDM Rubber Roof Repair Membrane, peel-and-stick, 6 in or 12 in wide by 25 ft (533RM-6, 533RM-12) |
| A small puncture, crack or seam leak on almost any surface | DiSeal / Seal-Tite sealing tape, TPO white or aluminum foil |
| Seams, cracks or tears on a roof you are about to coat | Coating-Ready Cover Tape, 4 in x 50 ft, followed by two coats of Dicor coating the same day |
| Soft spots, sagging, membrane loose over a wide area | Not a patch job. Dicor's handbook says to make sure the roof is structurally sound and the damage isn't part of a bigger problem first |
Dicor's rules for any patch
From Dicor's roof care handbook:
- Make sure the roof is structurally sound and the damaged area isn't part of a bigger problem.
- Don't patch over a previous patch, and don't repair with multiple patches.
- Trim any loose or protruding material.
- The patch must extend two inches beyond the hole in all directions.
- Clean before you seal: remove all dirt, oil and debris with a cleaner suited to the roof. Dicor Rubber Roof Cleaner is made for EPDM, TPO, vinyl and fiberglass.
Patching with the EPDM repair membrane
Dicor describes the repair membrane as self-adhesive EPDM rubber with no asphalt, solvents or VOCs. Its catalog lists it for EPDM rubber, TPO, PVC, metal and fiberglass roofs. Dicor's steps:
- Clean the area with Dicor Rubber Roof Cleaner and let it dry.
- Measure the damage and cut the membrane at least 2 in larger than the damaged area on every side.
- With the backing still on, position the patch and mark its edges in pencil or chalk as a guide.
- Peel the clear protective layer and place the membrane over the damage. Dicor's handbook warns that once it is down, pulling it up means starting over with a new patch.
- Press it flat with a small roller, such as a wallpaper seam roller, working from the center to the edges until the whole patch is bonded.
- Remove the beige top layer and run a bead of Dicor lap sealant around the edge. The handbook specifies a 5/16 in bead of self-leveling lap sealant, then a couple of hours before you move the RV.
Don't try to cover a large area by butting strips end-to-end or side-to-side. Dicor says not to use butt joints with this membrane. If the damage is too wide for one piece of the 12 in roll with 2 in to spare on every side, have an RV service center look at it before you patch.
Sealing tape: DiSeal and Seal-Tite
Dicor's DiSeal sealing tape comes in TPO (white) and aluminum (foil) versions, both with a 22 mil gray butyl-rubber adhesive. Dicor's catalog says Seal-Tite tapes are designed for EPDM rubber, TPO, PVC, fiberglass, wood, plastic, steel or aluminum, and that they seal most leaks immediately and fully cure within 24 hours. Dicor's published data:
| TPO tape | Aluminum foil tape | |
|---|---|---|
| Backing | 6.5 mil UV-resistant TPO | Mill-finish aluminum |
| Application temperature | 32°F to 110°F | 35°F to 110°F |
| Operating range | -40°F to 220°F | -40°F to 220°F |
| Full bond | 24 hours | 24 hours |
| Peel strength | 17 lb per linear inch | More than 10 lb per linear inch |
Clean and dry the area first, as with any Dicor repair, and follow the handbook's patch rule: cover at least 2 in beyond the damage on every side. Dicor's catalog lists the TPO tape in 4 in rolls of 12.5, 25 and 50 ft, plus 6 in rolls and 6 x 6 in patches; check the listing for the sizes we carry.
Coating-Ready Cover Tape: only before coating
This is a fabric-backed sealing tape that Dicor makes for seams, cracks and tears on a roof you are about to coat. It seals on contact and cures in 24 hours, and Dicor lists an application range of 35°F to 110°F. Its rules are strict:
- The roof must already be cleaned with the right Dicor cleaner/primer and be free of moisture.
- Position it carefully; repositioning damages the tape. Don't stretch it.
- No butt joints to cover big areas.
- Press from the center out, removing bubbles; the edges must have no tunnels, openings or "fishmouths".
- It must be followed by two coats of Dicor roof coating, and only applied to areas you will coat the same day.
Peel-and-stick patches are different: Dicor's handbook says they can go on one or two days before coating. See how much Dicor roof coating you need.
Bubbles are not tears
Dicor's FAQ says air bubbles in a membrane usually appear during or soon after installation, come and go with weather and humidity, and do not affect the roof's performance. Dicor asks owners not to puncture them: they give the membrane room to expand and contract, which lessens the chance of stress cracks later. Don't patch a bubble.
How long a patch lasts
Dicor's FAQ says that if a repair is applied properly, the patch should last as long as the membrane, and it should be checked periodically. Include patches in the same inspection you give your sealant, and press on them: Dicor's handbook suggests feeling patched areas for softness.
FAQ
Can I glue a new piece of rubber over the tear with bonding adhesive?
No. Dicor says its water-based bonding adhesive must not be used to bond rubber to rubber; it needs a porous surface to cure into. Use the self-adhesive repair membrane instead.
Do I need lap sealant around a peel-and-stick patch?
Yes, for the EPDM repair membrane. Dicor's directions finish with a bead of lap sealant around the edge.
Will these work on a TPO or fiberglass roof?
Dicor lists both the repair membrane and the Seal-Tite tapes for TPO, PVC, metal and fiberglass as well as EPDM. If you are not sure what your roof is, see how to reseal an RV roof by roof type.
Where can I get everything for the job?
Our Dicor collection has the patches, tapes, sealants and cleaners, and the Dicor roof reseal kits group them by roof type. Found it cheaper? We'll beat it.