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wealthwise's avatar
wealthwise
Explorer
Feb 15, 2015

Do I need a whole Roof Over?

Recently here in the Pacific Northwest we had a lot of rain, and I recently noticed water discoloration in the rear bedroom, it looks like rust if you see the photos you can see what I mean, I checked cabinets inside for further signs of discoloration but found none. First off what can I use if anything to restore/clean that and second and most important I looked at the rear roof, including photos here, and found the seals on the roof wearing down and there are gaps, do I just clean up and remove any old seals, replace with silicone and then cover with Kool Seal Elastometric, do I need to use a primer first?

Thank you for any help.













  • Agree'd - Never use silicone on the roof. Never.

    The good news is you roof membrane looks to be in good condition - the white surface looks good and there's no area's where the black material underneath is showing through from wear or sun damage. Just make sure the wood underneath it all is sound.
    It just needs a good cleaning (so the Dicor and Eternabond will stick) and some attention to all the seams and things that are mounted up there. I would cover that entire seam where the tape is coming up with fresh Eternabond.
    But clean first.
    And no silicone ANYPLACE.
  • wealthwise wrote:
    ... do I just clean up and remove any old seals, replace with silicone and then cover with Kool Seal Elastometric, do I need to use a primer first?

    Thank you for any help.



    Not trying to be disrespectful, but the above is 100% wrong. DO NOT use silicone. Silicone will stop holding after a few months in the sun on a rubber roof. Use Dicor self leveling caulk.

    DO NOT use Kool Seal. Kool Seal will dissolve when there is a standing puddle on the roof. These are the normal spots that leak on an RV. The place you need protection the most will be compromised by using Kool Seal.

    Instead use a product like this one that can handle puddling:

    Plas-T-Cote

    If I had to guess I think you have a leak around your rear ladder connection to the roof and/or the rear cap to rubber roof point. These are common weak point on older rigs.
  • If the ceiling is covered with a kind of carpet type fabric.

    I have had great luck with Folex, just spray it on and BLOT don't rub.

    It may take more than one application but it took out all of my water stains.
  • 1994 rig! I would say it should get a complete roof with old removed. There could be wood damage.
    Could get by with a roof coating. Clean off all the loose sealant and clean roof good areas and apply a roof coating that is compatible with rubber roof.
  • Throw the tape away. I would re do everything on the roof. If you dont remove the caulk, you at least have to make it good clean enough that the new Dicor self leveler will adhere to the old. Even if you try to remove it the surface will still be very irregular as it's just about impossible to get it all off.

    If there are strips or flaps of sealant that are loose you want to remove that stuff. Clean it well and use a small scrub brush so all the cracks come clean than use a leaf blower or let it sit in the sun long enough to be sure all the cracks and crevices are dry before applying the Dicor. I would agree that now is the time to look at all the plastic up there and replace as needed. It wouldn't be surprising that the water damage is down the walls and possibly to the floor. It all depends on how long it has been like that. If you notice ridges or wavy sections under the membrane it's because the plywood is coming apart and buckling. If it's still all smooth that would be a very good sign that the damage is limited.
  • First I would check to be sure the substructure is still sound...then if it is remove all the old sealant and reseal with dicor lap sealant. I would also replace the vent protrusion fittings if they are plastic as the will deteriorate over time and crack letting the pipe flex too much. I am not a fan of Eternabond as I have seen too many failures with proper install. This was also stated to me by my manufacturer...JMHO.
  • Remove all old sealant and reseal. Those cracks and gaps in sealant are your
    weak areas.

    it only take a pin head hole to become a leak.
  • I'd suggest you remove the failed sealant and replace it with Dicor lap sealant or Eternabond tape. BTW, there is no good use for silicone based sealers on an RV.

    You could try a fabric-friendly rust/stain remover on the interior. Don't know how successful that will be but probably worth a try if the ceiling only has a few spots.

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