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Topic: Class C overhead Cabin Leak
Posted By: bill257 on 09/26/17 11:59am

I have class C Motorhome, Coachman Freelander BH 32 2011.I have a problem with leak in the overhead cabin.I got it checked last year at the RV Service Shop.They checked it out with some instrument which check the leaks in the Cabin.Resealed the cabin area.This year again I have noticed water under the mattress.I do not know what to do.Any suggestions.

Posted By: midnightsadie on 09/26/17 12:17pm

call a mobil tech there faster, smarter, cheaper, and will find the leak.

Posted By: rockhillmanor on 09/26/17 12:19pm

Same here found wet spots under overhead mattress.

The water was coming from the weep holes of the windows on the side of the cab over.

I also got to see it first hand during a rain storm. The water was pouring down the side from the window weep hole on one side.

Went outside and could see the water just pouring off the roof down that side. My MH was not perfectly level so the majority of the water on the roof was coming down on 'that' side and the weep hole could not handle it.

I ran my front tire up on just one leveling block on that side and it stopped coming in.

Sooo....
1. The weep holes could be plugged with dust dirt leaves etc. So the water will come in.

or

2. MH not level during a real good down pour of rain.

We must be willing to get rid of the life we've planned,
so as to have the life that is waiting for us.

Posted By: SidecarFlip on 09/26/17 12:24pm

First thing you need to do is take it to a competent RV repair facility that can do a 'Blower Door Test', or in the case of an RV, an authorized Seal Tite Systems franchised dealer and have them perform the test and isolate (and mark) where the outside seals are failed (why it's leaking). Once you do that, you need to ascertain how bad the water intrusion is, how much under the wallboard rot there is, if there is a mold issue (most likely) and remediation cost and if the cost is worth it or nor. It's not cheap by a long shot and the unit may not be worth the cost of repair.

Seal and caulk continuing maintenance is the most important thing concerning RV ownership, seals and caulk must be inspected every 6 months or what happens is what you have... water intrusion and most likely rotting structure, soaked insulation, mold growth and a serious issue.

2015 Backpack SS1500
1997 Ford 7.3 OBS 4x4 CC LB

Posted By: ksg5000 on 09/26/17 01:17pm

Cabover area of Class C's are common source for water issues. Sometimes it's the front facing windows (PIA to fix), sometimes it's just the side windows which can be removed/re-caulked, sometimes it's the running lights, roof antennae etc.

Finding the leak source is priority 1. If me I would spend $100 or so and have the rig pressure tested - should identify all the leak sources and save you much time. In the interim I suggest you park your rig so the front is at least a couple inches higher than the back - this will encourage rain to shed away from your likely leak source - might help until you find/fix the problem.

In my case the leak source was a side window - I watched a youtube video on how to fix and it was 1 hour easy fix. So easy I did the same for all the windows when I had some free time.

Water leaks in the cabover area will migrate to the lowest level - that's often the front nose of the cab area - depending on the rig you might be able to drain that area by removing some trim which runs on the bottom of the cabover above/front of the front chassis window. Regardless - make sure you don't have standing water or wood rot your cab area .... zillion posts on this type of issue.

Kevin

Posted By: SidecarFlip on 09/26/17 02:43pm

On e of the best and least intrusive methods for determining if there is rot and mold under the wallboard without doing a destructive examination is use a non contact IR thermometer and shoot a known (dry) wall and then shoot the front wall where the water is or where you think it's coming from.

If the IR says it's a couple degrees warmer than the known dry wall. You not only have a leak, you have rot,or soaked insulation or mold growing, probably all 3. Mold creates heat, rot creates heat, soaked insulation molds and creates hear. That space is dark and waem, great for growing mold.

Posted By: bill257 on 09/27/17 08:02pm

Thanks for everyone's response.I did get it pressure tested last year and after that Technician at the RV Shop sealed the areas.Still it did not work.I took it again to a different RV Shop.Technician inspected the roof and top of cabin area.Initially he said it is difficult to say where the leak is but you can reseal the whole roof.I said to him I have no issues anywhere else except the overhead cabin.Than he said he can reseal the cabin area,all front lights and also two side windows.I told him that I did get it resealed last year and he said whoever did it just put the seal on the old one.I will scrap the old one and put new one.It will take 6-8 hours of labor and 40 dollar of material for just cabin area including top lights and side windows.Approximate cost about 720 dollars.110 dollars per hour labor charge.Is this is reasonable or too much.

Posted By: SidecarFlip on 09/27/17 08:11pm

Considering our shop charges a flat rate of $135 per hour on RV related repairs, I's say it's reasonable, however, you can do that yourself. I'm 68 and I would have no issues removing old caulk and resealing the seams, popping clearance light fixtures and resealing them or recaulking windows. It's not hard, materials are available online and some Lowes have them and tools are basic. Scraper or stiff putty knife and a screwdriver or square drive bit for drive screws and some rime on your part.

Best part about doing it yourself is, you'll know it's done right because you did it.

Posted By: bill257 on 09/28/17 06:52am

I just have a side question.My Class C is 7 years old and only 17000 miles on it.I regularly inspect my roof and clean it.Is it time to reseal the whole roof with Rubber liquid or any other suggested product.What caulking should I use for edges, antennas, vents etc.My roof is rubber but does not know whether IT is EPDM or TPO.Does it matter if I want to use Rubber Liquid by DIY?

Posted By: DrewE on 09/28/17 07:08am

I would not think the rubber needs coating (what you're calling resealing) after seven years unless your cleaning regimen involves a whole lot of scrubbing, etc and has worn off the white outer surface.

The two standard products used to seal seams and protrusions and such are Dicor Self-Leveling Lap Joint Compound (which requires periodic inspection and renewal/coating over as it ages) and Eternabond tape. The Dicor product is only for horizontal surfaces; it's runny rather like yogurt as it comes out, which is how it self-levels, and eventually dries to something around the consistency of used chewing gum. Eternabond tape, properly applied, is said to last longer, but it does require following its directions fairly carefully.




Posted By: bill257 on 10/05/17 05:23pm

I talk to a mobile Tech who will bring with him a special machine to check the leak and he was confident that if there is a leak he will find it and mark it out. Once the leak I will ask advice how to seal it.I will keep you all updated.

Posted By: navegator on 10/05/17 05:37pm

I have a C and I found that a bird strike on the center marker light cracked the plastic and when it rained water would seep in, only when parked, drove from McAllen to san Antonio in a down pour and no water entered, overnight in San Antonio it rained and we had water under the mattress, I used that clear tape used for the awning on all marker lights until I could replace them, once replaced no wet mattress, and if you are wondering no I did not wet the bed!

navegator

Posted By: SidecarFlip on 10/05/17 05:53pm

Once again, it's not the wet mattress but the path it took to get there is what is important. To get from the outside to the inside it has to get between the outer skin and the inner wall and along that path, it soaks the insulation and the wood substructure. That is where the issues are.

Just because you fix the leak, the water has already permeated and soaked the insulation and wood so things start growing (mold / mildew) because it cannot dry out. It really only takes one soaking and the mold / mildew starts growing.

Posted By: my440 on 10/06/17 09:45am

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.




Posted By: SidecarFlip on 10/06/17 10:06am

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.

Posted By: bill257 on 10/10/17 07:49pm

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.

Posted By: bill257 on 08/06/18 12:06pm

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.

Posted By: bill257 on 10/22/18 01:48pm

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.

Posted By: lfcjasp on 10/22/18 03:23pm

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[emoticon]) 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...

Posted By: 30sweeds on 10/25/18 08:12am

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...

Posted By: garyhaupt on 10/25/18 10:19am

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

I have a Blog..about stuff, some of which is RV'ing.

http://mrgwh.blogspot.ca/

Posted By: TheBar on 10/25/18 01:33pm

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.
[image]

* This post was last edited 10/25/18 01:49pm by TheBar *

Retired factory automation computer programmer
Cabin fever solution: 30' Class C
DW loves it more than I do

Posted By: CapeDave on 11/07/18 09:51am

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.

Posted By: lfcjasp on 11/07/18 12:50pm

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[emoticon]

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