Class C overhead movement causing seal failure

[Juzaxadar]

I'm posting a couple of pics of the corners of my overhead bed.

This is a 2000 Winnebago Minnie 31C.

During a recent 5500 mile trip, I saw a lot of flex happening above the cab. When I got back, I noticed that the corner seal has come loose. I had sealed it with ProFlex about a month before taking the trip, so I know it was good.

The corner (temporarily re-sealed today)


Any ideas about how to limit the flexing or to seal it so that the flexing doesn't break the seal? I can re-seal over and over without much effort or cost, but it failed about halfway through the trip making any long trip a potential cause of leaks.


Secondly is that I have a split in the side of the tip of the overhead camper cab. The split is top to bottom and is about 6 inches tall. It was sealed with as much ProFlex as I could get on it before the trip because I didn't have time to fix it correctly. It also came unsealed because of all the flexing going on during driving.


I was thinking about using EternaBond to fix this on the outside, and possibly even putting a strip on the inside to make it as tight as possible. Short of a professional fix, does anyone know of a better way to repair this?

I will clean and repair these as soon as I recover from the trip, but want the work to be worthwhile.

[Mich_F]

The bunk board is flat. If you look at the picture I posted on 12/1, you can see a side view of the front wall. That wall is a combination of a couple pieces of wood going across the front (mine were rotted and had to be replaced) and foam. The foam is notched so that it can be bent around the corners. Our foam was salvageable. The bunk board is secured at the walls behind both cab seats and around the cab roof cut out as well as to the bottom of the side wall wings.

[Juzaxadar]

7 months, ouch... But I know how it is.

I would love to know how the front bunk board attaches, the cabover walls too. I don't have the time or skill to do a complete rebuild of the cabover, so if I can't get those pieces in and out without detaching the outside fiberglass, I won't touch it.

OK I actually know how the front bunk board attaches at the center using the cross bar that keep the fiberglass up. What I don't know is how the front of the front bunkboard attaches. Is is a curved board ?

[Mich_F]

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(Can't link just one picture) :?

Haven't made very much progress in the 7 months since I bought this MH.
My son (who's doing the rebuild) has been busy rebuilding a number of other RVs. We managed to salvage the front wall after we removed the rotted wood that was in it. The piece is just hanging there, secured across the top. We will have to put another piece of filon over it, because there are a number of screw holes in it, as well as a hole or two that resulted from removing the bad wood
A new bunk board has been built, but hasn't been installed yet. The fiberglass on the passenger side cabover was peeled back to examine the wall, but will be reglued, since it's fine. The driver's side had to be totally rebuilt.

[Juzaxadar]

Mich F, Did you do a rebuild yourself? Got any pics?


I see some small spots on the inside carpeting from the cabover lights. It looks like the last person who sealed them sealed the top (protecting from gravity fed water) but didn't seal the bottom (protecting from wind driven water).

I've been taking the screws and trim pieces out of the cabover in the past week or so and it looks like the "floor" of it is split into two sections. The rearward section is trimmed into the E-450 cab and looks like it has the least trouble. Because of the connection with the cab, I'm going to leave that alone. I don't want to mess up the seal above the driver window.

The front section of the cabover looks to have a medium amount of water damage. The curved wall pieces up front being the biggest issue. It's pretty soft. The flooring of the front piece has had some water in it too.

The front driver-side wall in the cabover has all of the screws out. It's build out of about a 1.5" thick white styrofoam with a real thin wood panel over it and then a plasticky wallpaper on top of that. Even though all the screws are out, I can't get it loose enough to look behind it. I'm not sure how it's attached. Could be glued to the outside fiberglass I guess...?

At this point, I know I can seal the outside pretty well with eternabond, and unless it's driven, it's covered. Further damage is unlikely, but it'd be nice to seal the inside of that fiberglass as well and replace the styrofoam and/or the wood.

[Mich_F]

EMD360 wrote:

Mich F wrote:
More than likely your side walls look like this, which is on a 2001 Itasca Sundancer 31C

Yikes--that rig is really rotted and it has no front window. Guess that isn't the preventative some hope for.
Could you tell if the rot was a result of failed side seams or roof seams?

If I remember correctly,(we took this apart last June) all or at least most of the leaks were on the roof/sidewall seam in the cabover, on the driver's side. I don't think the front clearance lights showed any signs of having leaked. We didn't care where it was leaking, since I bought it, knowing the cabover needed a total rebuild.

[pnichols]

.... or maybe the rot was a result of failed cabover running lights' seals.

[EMD360]

Mich F wrote:
More than likely your side walls look like this, which is on a 2001 Itasca Sundancer 31C

Yikes--that rig is really rotted and it has no front window. Guess that isn't the preventative some hope for.
Could you tell if the rot was a result of failed side seams or roof seams?

[DrewE]

My '98 Coachmen does have a couple of aluminum framework bars across the front of the cabover that I assume are welded into the rest of the framework. They go immediately above and below the front cabover window. I would think that any cabover with a front window would need some sort of framework around that window, be it wood or metal, and not just the foam and fiberglass and luan or whatever the walls are constructed of. There's also some wood formers for the lower curve of the front of the cabover. Manufacturers do, of course, differ in their handling of such details.

I've never noticed what I would consider excessive flexing. There are occasional creaks from somewhere in the general area (which may just be the gasket between the cab roof and the house part).

And like the others have said, the vinyl trim in the corner molding is there mostly for visual effect; it's not waterproof, and isn't the primary seal for the corner. The real sealing comes from butyl (or something similar) underneath the metal corner extrusion.

[Travelcrafter]

The problem of managing a leak is the fact that more often than not that leak has been there far longer than it has been detected. Your just managing the resulting effects. There is a real danger in the lack of structural integrity of your unit not to mention the environmental concerns you have in the form of black molds and other toxins that lurk in wet/damp environments. Your not alone for sure, it's a common enough problem but I would encourage you to at least pull the inside paneling off and do a thorough exam of the side structure. you may also want to limit the use of the cab over to light loading. common since I guess but just a suggestion. Good luck with it though and Mary Christmas/Holiday

[Juzaxadar]

Thank you. That picture is useful. I will be able to weld those if I find it.
But I agree with snowman. For the money I can manage around a leak for a long time and still enjoy the trips.

[Mich_F]

More than likely your side walls look like this, which is on a 2001 Itasca Sundancer 31C
As you can see, other than the outside framing there are only a couple of small braces which are welded to the main framing. A weld on one of these corner braces was broken. The front wall has no metal framing. It's just a combination of a fiberglass exterior panel, along with wood and pieces of foam.

[mikeleblanc413]

Many excellent comments here! I have a 2000 Winnebago Minnie Winnie DL and have "managed" a cabover leak since purchase in December 2011. My shortlist when looking to purchase my Class C was to have a cabover that had nothing in it so that if I had a leak it would be easy to spot and not have to pull out a lot of stuff. Weeks after purchase I had a water soaked cabover. I removed the front part of the foam, dried and put a foam piece in that could easily be removed. I've managed that area for 3 years and have now Eternabonded the seams that the OP is speaking about. I had earlier Eternabonded the roof seams. If I had it to do over I would have Eternabonded everything and not dealt with Dicor (or similar) sealer. In the meantime we have traveled 23 states and over 20,000 miles and have more planned. I continue to get my moneys' worth from the purchase. What a DANCE!!!!!

[Snowman9000]

The drooping "seal" is just a look-good thing called vinyl trim. It is meant to cover the screw heads but it is not waterproof. Even though RV makers treat it like it is. 😞

The aluminum corner trim can be the source of the problem. And by problem I mean leak, and rotted wood inside. Because the sidewall leg of the trim points up, it catches rain and channels it down to the flat portion. There you'll find wood, and screws going up into the wood. The rot begins from the bottom up. Pull that vinyl trim out, then remove a few screws. See if they will tighten back up, or what. If they won't, that's a sign of wood rot.

Caulking the edge of the corner trim is a great idea. In this case it's probably way too late to do any good though.

[Juzaxadar]

It's certainly possible.
I have yet to disassemble the inside to see what's there. Been far too busy.

I've never taken it off-road. I can't imagine what would cause a weld break or serious structural damage aside from an accident or off-road use.

[Mich_F]

Juzaxadar, it is possible the welds have broken on the side walls of your cabover, resulting in all that flexing, you are experiencing.