Forum Discussion

Frankandbeans's avatar
Frankandbeans
Explorer
Sep 04, 2015

Repairing soft spot in RV roof

OK, first off I apologize as I know this is not a new topic. However, the standard "search, it's been covered x amount of times" is rather quite useless when the links are 5+ years old and none of the pictures work. I have roughly a 1.5' square foot soft spot in the corner of my toy hauler. I can tell it leaked right at one of the seams, as there is undoubtedly a clear, straight line where the roof is solid then gets soft. I did find a small tear in the EDPM roof (branch or something must have tore it since I checked it in the beginning of the year).

So my question is:

How exactly do I make the cut into the roof to access the rotten wood to replace it? Should I cut a "H" pattern? I can probably figure out how to replace the wood once I get to that point, but my question is how/what do I use to glue/repair the EDPM roof? Is it acceptable to use Eternabond and just "seal" the roof back together? I am still trying to figure out what the "good" products are out there and what route I should go with.

9 Replies

  • MdMike1007's avatar
    MdMike1007
    Explorer
    Nov 10, 2015
    I have a similar issue but will be repairing it this week and tearing off the entire rubber roof and replacing it with a spray on beeliner like roof. My soft spot is in a corner like yours but there is no tear. These guys will replace the rotted wood, inspect for further damage and over lap spray the seams in sides and ends of camper. 20 year warranty and no more caulking! Will post pics as job progresses and is completed.
  • Frankandbeans's avatar
    Frankandbeans
    Explorer
    Oct 27, 2015
    bobbyclobber wrote:
    Frankandbeans wrote:
    Thanks for the reply. So it is on the edge of the membrane (Where the rain channel on the side is). How far off would my plan be in this case?

    - Remove that rain channel to remove the screws/staples on the side holding the EDPM down.

    - Cut two slits in the rubber roof so that I can peel up, starting from the edge obviously, the roof allowing me to access the rotted wood.

    - Repair wood and use whatever EDPM glue to adhere roof to the new repaired wood.

    Now the big question - what about the seams from the cuts? Obviously it should be mostly sealed from the glue that I would imagine would overflow out of the cuts, but just to verify, I can just use the Eternabond tape to seal that seam, right?


    I have the exact same problem , soft area , similar size and scope , and was wondering how you made out. I'll probably do the same procedure with mine, thanks, Bob


    Getting too cold to work on it...put a tarp covering the entire roof so it's covered for the winter and will mess with it in the spring.

    I believe I did find the cause of the leak, a very small (1/2" or so) tear in the EDPM, probably from a tree branch or something. I used some Eternabond and that Flex-seal stuff ("as seen on TV") to patch in the mean time.

    Maybe if I'm really lucky, a Shark-nado will hit the area and I can file a total loss claim with my insurance company, claiming the trailer got destroyed by flying sharks. Then I'll go back to an enclosed trailer and not have to deal with this stuff anymore.
  • RVcircus's avatar
    RVcircus
    Explorer II
    Oct 27, 2015
    Be sure to inspect for additional rot/water damage beneath the plywood. When I went to fix my roof corners it turned into an entire roof, the rear half of the trailers walls, and 6' of floor joists. It's amazing what secrets siding can hide if you don't look closely.
  • bobbyclobber's avatar
    bobbyclobber
    Explorer
    Oct 27, 2015
    Frankandbeans wrote:
    Thanks for the reply. So it is on the edge of the membrane (Where the rain channel on the side is). How far off would my plan be in this case?

    - Remove that rain channel to remove the screws/staples on the side holding the EDPM down.

    - Cut two slits in the rubber roof so that I can peel up, starting from the edge obviously, the roof allowing me to access the rotted wood.

    - Repair wood and use whatever EDPM glue to adhere roof to the new repaired wood.

    Now the big question - what about the seams from the cuts? Obviously it should be mostly sealed from the glue that I would imagine would overflow out of the cuts, but just to verify, I can just use the Eternabond tape to seal that seam, right?


    I have the exact same problem , soft area , similar size and scope , and was wondering how you made out. I'll probably do the same procedure with mine, thanks, Bob
  • westend's avatar
    westend
    Explorer
    Sep 05, 2015
    I think you have it but it may not be necessary to cut any slits in the membrane. A lot depends on where the repair needs to be done. The metal trim edge on the roof and the adhesive is what holds the membrane in place.

    when you reattach the trim edge use stainless fasteners and/or seal the fasteners in the holes. Fastening through Eternabond tapes seals the fasteners, too.
  • BarneyS's avatar
    BarneyS
    Explorer III
    Sep 05, 2015
    Frankandbeans wrote:
    Snip...
    Now the big question - what about the seams from the cuts? Obviously it should be mostly sealed from the glue that I would imagine would overflow out of the cuts, but just to verify, I can just use the Eternabond tape to seal that seam, right?

    That is exactly what I would do. The Eternabond tape will seal up the cuts. If you want to make absolutely sure, just put a bead of Dicor self leveling caulk on the edge of the tape after you put it down and rub it in.

    That step is probably not necessary however. I used Eternabond tape on all the seams of my trailer 8 or 9 years ago and it still looks like new and does not leak. I did not put caulk on the edges. Your plan looks good to me. :)
    Barney
  • Frankandbeans's avatar
    Frankandbeans
    Explorer
    Sep 05, 2015
    Thanks for the reply. So it is on the edge of the membrane (Where the rain channel on the side is). How far off would my plan be in this case?

    - Remove that rain channel to remove the screws/staples on the side holding the EDPM down.

    - Cut two slits in the rubber roof so that I can peel up, starting from the edge obviously, the roof allowing me to access the rotted wood.

    - Repair wood and use whatever EDPM glue to adhere roof to the new repaired wood.

    Now the big question - what about the seams from the cuts? Obviously it should be mostly sealed from the glue that I would imagine would overflow out of the cuts, but just to verify, I can just use the Eternabond tape to seal that seam, right?
  • westend's avatar
    westend
    Explorer
    Sep 04, 2015
    Usually. you can lift the EPDM membrane off the rotten roof sheathing if the damage is towards the edge of the membrane. Some rotten wood may stick to the underside but is easy to remove. After completing the wood repair, glue the membrane back down with EPDM adhesive.

    Tears or cuts can be repaired with Eternabond tape.

About DIY Maintenance

RV projects you can tackle on your own with a few friendly pointers.4,382 PostsLatest Activity: Jul 24, 2025