problem finding the cause of a roof leak

A rv repairman told me to remove all suspected caulking-CLEAN WITH MINERAL SPIRITS-then apply Dicor to rubber type roof and apply a good silicone sealant to fiberglass roof parts.

Turns out my "leaks" I am now sure are condensation problems.

I went around my shower skylight with Eternabond tape. I brought the tape up a few inches on each side of the dome.

CPaul, you were on the spot. Crack around the bottom edge near a corner. Verified it was there by using my knife to find the separation. Sealed everything to the top edges and after last nights rain storm it was dry! Hopefully no problems till i get back home and I am going to redo everything and fix that skylight.

Had a leaking skylight over the shower that I tried sealing everything in sight. Flange around it, every screw head I could find and still leaked.
Finally located a tiny hairline crack in the corner of the skylight itself, very difficult to see. A bit of sealer tape stopped it. Will replace the entire skylight later.

Sue Bee wrote:
Just because you have a leak coming out one place doesn't mean that the water isn't coming in somewhere else and seeking it's level.

Your AC unit, that skylight, any intrusion in the roof is suspect. But we've had a never ending issue with our ^%$@!!! Heki Skylight in the Bigfoot leaking because the thing is so stupidly designed and installed. ***I*** could have designed and installed that thing better in my sleep. And any time we take a trip with the Bigfoot, it is time to check the seal around it, because it seems that the Plasticote doesn't flex well.

Is the Eternabond tape more flexible than the Plasticote goo? I might just bite the bullet and try that.

Sue Bee mentioned the AC. Have you ever gone back and tightened the 4 bolts inside the AC cover? they often wiggle loose and need to be re-tightened periodically. Your water may be getting past your AC/Roof gasket and running toward the bathroom. It's a good thing to check anyway.

Just because you have a leak coming out one place doesn't mean that the water isn't coming in somewhere else and seeking it's level.

Your AC unit, that skylight, any intrusion in the roof is suspect. But we've had a never ending issue with our ^%$@!!! Heki Skylight in the Bigfoot leaking because the thing is so stupidly designed and installed. ***I*** could have designed and installed that thing better in my sleep. And any time we take a trip with the Bigfoot, it is time to check the seal around it, because it seems that the Plasticote doesn't flex well.

Is the Eternabond tape more flexible than the Plasticote goo? I might just bite the bullet and try that.

bobndot wrote:
scroll down and look thru 'members projects' in TC university ... to see if there is a home-made version of the seal-tech testing system.
An rv shop will charge about $150-200 or so to do the seal-tech test .

http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/25966285.cfm


seal-tech explained with pics

When I had my roof leak, I covered the vent with a Rubbermaid container turned upside down , then used a sprinkler to see if it leaked when it was covered. If the leak stopped then you found the culprit.
I used Eternabond tape once I was 100% sure where the leak was coming from. Its difficult to remove that e-tape once its in place .

Good luck, I hope you find it , Bob

And here is the Low Pressure Test
Hope you have or can borrow a leaf blower.
Good Luck

Joe, I did the mounts when I was up there. Actually did the entire roof wherever there was something going thru it. Going back up this weekend woth a hose and some weighted plastic bags to test it. Using the bags to make a isolation wall as I go. Maybe I will find it that way.

I had a similar issue. My leak was a small crack in the sealer on the bath vent. It would take a while to leak unless it came a down pour.(Or I flooded it with a water hose)

I removed the skylight completely. That let me see the path the water was taking. The water carries dirt and in my case green algea to mark the path. Obviously, it had been leaking for some time.

It came in and ran under the Dicor along the back edge of the vent fan. The water then ran under the butyl putty at the left rear corner of the skylight, dripped down and ran across the inside face frame of the skylight and dripped out on the right side.

It was easy to reseal. But resealing the skylight would not have fixed the problem permanently with out resealing the vent.

From your description of where the water is dripping, there are also the roof rack mounts approximately over the door, with one almost touching the skylight. (I'm assuming the same floor plan as my 05 model)

I have a mental issue with just stopping the problem, I usually make an experiment out of it. But that way I know it's done right and how it's put together.

Good luck,

x3 on the Eternabond Tape.