Class C overhead Cabin Leak

Our camper is going into the shop Friday for a leak issue in our cabover (second time in 5 1/2 years). DH has caulked all over every seam he can find and we still have this leak...will be contacting our insurance most likely and hope they help again:)

I would have a close look around the vent!
Remove the plastic cover and check the sealant very carefully.
My last leak was hidden under front where it hinged, until I
disassembled and removed the plastic dome I could not find the leak.

I highly recommend using Eternabond tape around all roof vents, the roof sides, over the front and back caps, and covering the cabover trim that curves over the front from the roof to the back of the cab. Then forget about caulking roof seams and sealing the trim for 30 years. If you work slowly and carefully and use smaller widths of the tape where needed it looks good. I used three 1" strips overlapping to cover the cabover trim. After this picture was taken I painted the gray sticky adhesive sides of the tape and it now looks not like factory, but like white trim that came from the factory. I cut the tape down to 1/4" and sealed around front window and the clearance lights.

Sometimes we overthink stuff. Have you had the RV out driving in wet conditions? If so...the front clearance lights are the common culprit. They have a sealant that gets beaten by weather and dries out. And if you are driving into rain at 60+mph, it can and will force it's way in. And then the side windows.

I looked at Google for your coach and don't see a front window. They are THE worst.


Gary Haupt

bill257 wrote:
I got the Rig pressure tested couple of weeks ago and found lot of spots in front cabin area with leak.They all now sealed.

Hope everything works out for you. Not trying to scare you but here's my experience with the same deal.Got mine pressure tested,found the leaks,sealed them up,everything good.Had a little staining on a removable panel under the front window that annoyed me so I thought I would remove it and clean things up.Saw some black stuff under the panel so dug a little deeper.Well...as it turned out,all the wood framing including the front top and bottom roof corners was completely rotten and moldy to where the floor meets the cab.The only thing holding it together was the waterproof foam insulation being glued to the luan flooring.The sidewall was actually starting to separate from the bottom fiber glass.There was standing water on top of the bottom fiber glass panel and it hadn't rained for weeks.After 3 weeks of complete reconstruction,it's better than it ever was from the factory.Just telling you what can happen...

my440 wrote:
My overhead bunk mattress was damp with mold. Searched everwhere for the leak.
Turned out to be dampness formed by warmer underside of the mattress meeting the coolness of the cab directly underneath.
Installed a insulating styrofoam board under mattress which helped plenty.
May not be the case here but worth mentioning in case someone else may wonder whats up with the moldy underside of mattress.

We found mold/mildew under the cabover mattress this past summer; it hadn't been hot so much as HUMID, really, very, hideously HUMID. We figured that plus the temp differential between cab and cabover and the lack of air circulation up there were all the culprits.

DH cleaned and cut some PVC pipe and laid it up there under the mattress (after we cleaned all the mess up:() and so far so good. Of course summer finally left and temps and humidity have been mercifully lower. The fix may not look so great, but it works and that's what counts.

I'd just as soon take the mattress down and store it elsewhere as we have only used it as bunk a couple times in six seasons, but DH says it can stay up there. We only use the area for storage...

I got the Rig pressure tested couple of weeks ago and found lot of spots in front cabin area with leak.They all now sealed.

I started this thread last year and get my Rig pressure tested.After that I was still noting some water under the matterss in the overhead bunk.This year what I did different is that got my Rig parked in a position with front end at higher level than the back.So far I have not seen any water in the front overhead bunk bed area.We have lot of rain so far here in Maryland but no trace of any water.Does just changing the position of the Rig how parked did the trick or something else.Any comments/Suggestions.I have scheduled another pressure test later in September this year.

As it is said in the post earlier about Non contact IR thermometer so I bought one and check the Temperature in all the walls and than the front cabin.It is reading same everywhere.Does it mean I do not have any significant rot/mold behind the walls is the front cabin.

my440 wrote:
My overhead bunk mattress was damp with mold. Searched everwhere for the leak.
Turned out to be dampness formed by warmer underside of the mattress meeting the coolness of the cab directly underneath.
Installed a insulating styrofoam board under mattress which helped plenty.
May not be the case here but worth mentioning in case someone else may wonder whats up with the moldy underside of mattress.

When occupying any unit, you always need to provide interior ventilation, especially when sleeping because you aspirate moisture when you occupy any unit.

I know it sounds counter productive to have windows open when it's hot out or cold out, but it's necessary. An RV unlike a house is pretty well sealed up from ingress and egress of air. You have to allow for ventilation at all times.

Condensation will collect on a colder surface, just like a cold glass of water collects moisture from the air on the outside of the glass.