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RVcircus's avatar
RVcircus
Explorer II
Apr 12, 2016

How we resealed our RV roof with Dicor lap sealant

Once again, spring is upon us and so are those RV maintenance chores! This week we climbed up on the roof to check all the seams and reapply Dicor lap sealant where needed.

For those that have followed along with us you’ll know that we replaced our entire roof (along with some walls & floor) about a year and a half ago. During that time we haven’t had any issues with the roof, but after dealing with the aftermath of water damage we know the importance of preventative maintenance. When we dewinterize in the spring we do a pretty thorough check of the RV and all the systems and nip any potential issues in the bud. One of our highest priorities is keeping water out of our RV!

As far as the roof goes, we first walk (or crawl) the entire roof looking for any damage to the rubber membrane. We then focus on all seams around vents, transitions, trim, etc. looking for cracks or holes that could potentially let water through. At this point we clean the seams and reapply Dicor lap sealant to anything questionable since it’s likely I won’t check again for another year. I apply new sealant directly over any cracks and only peel the old sealant away if it’s already hanging or coming off.

Here's a link to our video showing how we did it:
https://www.youtube.com/watch?v=vse5Fgo11fU

And here's a link to our blog post with more details if interested:
http://www.rvcircus.com/apply-dicor-lap-sealant-roof/
  • LarryJM's avatar
    LarryJM
    Explorer II
    Apr 15, 2016
    jake2250 wrote:
    Just a note on your sealant, I used to do the same around a roof vent like that, but after the second application of sealant it eventually built up a small ridge or berm trapping water between the vent and the sealant. After a heavy rain I climbed up to check my work and noticed that it was like a little mote!! Since then I use a wooden dowel to create an indentation at the corners to allow water to drain out and not sit up there..
    I eventually scraped the heavy bead of sealant off and used Eternabond Tape around my vents and joints.


    That IMO is ABSOLUTELY CRITICAL since except for some of the Marine sealants none are rated for submerged applications. This is again IMO the NUMBER ONE REASON and the ACHILLES HEAL in all TTs at each corner on the roof where the roof end seam meet the metal insert molding for the front/rear that runs up onto the roof. This forms an area where water WILL POOL regardless of how the trailer is leveled. The guaranteed failure of the caulk there is why almost all trailers eventually leak like the OPs did at one or more corners and take out two sides, the roof area and sometime the floor in that corner. I spent quite a bit of time in eliminating this issue when I Eternabonded by roof back in 2008. Now my corners are entombed in Eternabond and are sloped out from the corner to the sides so water cant pool in that area.

    Larry
  • RVcircus's avatar
    RVcircus
    Explorer II
    Apr 14, 2016
    jake2250 wrote:
    Just a note on your sealant, I used to do the same around a roof vent like that, but after the second application of sealant it eventually built up a small ridge or berm trapping water between the vent and the sealant. After a heavy rain I climbed up to check my work and noticed that it was like a little mote!! Since then I use a wooden dowel to create an indentation at the corners to allow water to drain out and not sit up there..
    I eventually scraped the heavy bead of sealant off and used Eternabond Tape around my vents and joints.


    Interesting tip, I've never heard of anyone doing this but it makes sense to give the water a channel to drain.

    I'm planning to replace my fans and will be doing Eternabond at that time. Until then, lap sealant is the most economical choice for me.
  • jake2250's avatar
    jake2250
    Explorer
    Apr 13, 2016
    Just a note on your sealant, I used to do the same around a roof vent like that, but after the second application of sealant it eventually built up a small ridge or berm trapping water between the vent and the sealant. After a heavy rain I climbed up to check my work and noticed that it was like a little mote!! Since then I use a wooden dowel to create an indentation at the corners to allow water to drain out and not sit up there..
    I eventually scraped the heavy bead of sealant off and used Eternabond Tape around my vents and joints.
  • RVcircus's avatar
    RVcircus
    Explorer II
    Apr 13, 2016
    jfkmk wrote:
    Nice tutorial. I haven't reseated anything on my roof yet, but I think it's on the to-do list this year.


    Thanks! I'd bump that to the top of the list if you haven't inspected the roof. After seeing the damage a roof leak can do keeping water out is our top priority when it comes to maintenance. The rear corner was leaking and the water rotted 1/2 of the roof, 1/4 of the side walls, there was no solid wood left in the rear wall, and a few feet of the floor and joists were gone. I'm not sure how long the previous owner let it go, but it was bad.
  • RVcircus's avatar
    RVcircus
    Explorer II
    Apr 13, 2016
    jake2250 wrote:
    Good job,,, gotta question,,,,How close to Philly are you?? I grew up there and took a beating on saying "Wooter" when I got out here,, matter of fact my academy class called me "Wooter Man",, They just don't understand!!


    Ha, good catch!!! I grew up about 10 minutes outside of Philly, so I sound normal to me.
  • jake2250's avatar
    jake2250
    Explorer
    Apr 13, 2016
    Good job,,, gotta question,,,,How close to Philly are you?? I grew up there and took a beating on saying "Wooter" when I got out here,, matter of fact my academy class called me "Wooter Man",, They just don't understand!!
  • jfkmk's avatar
    jfkmk
    Explorer
    Apr 13, 2016
    Nice tutorial. I haven't reseated anything on my roof yet, but I think it's on the to-do list this year.

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