cabover water damage

[chefdc1]

We were just out in the MH (1997 Damon Hornet) prepping to do some painting, when my wife decided to pull the sheets off in the cabover. That's when she noticed moisture. It had previously been bone dry. We had some heavy rains a few days ago, so somehow, water made its way in. The bottom of the mattress cover was wet, as well as the foam. Not soaked, but wet. The wood underneath is also wet, but definitely not rotting through...yet. The wall to the left of the front window also seems less than perfect. I pried up the wood a little and the Styrofoam underneath is also damp.
Obviously, my first step is to find, and stop the leak. I'm assuming it's coming from the front window. The caulk around it does not look perfect. It's dark now, so I will examine a lot more in the morning.
Okay, now are the beginning of my many questions:
Assuming the leak is around the window, what type of caulking should I use?
How difficult is it to pull the ply up, replace the styrofoam and plywood?
How difficult to pull the front inside panel around the window?
Nothing is rotted through, so I think we're catching the problem early.

[Snowman9000]

I was in the same boat when we bought our first fifth wheel. My thread here was titled something like "minor leak question". It turned out to be a big project involving rot repair and several leak points.

Whatever you do, don't just caulk or tape over something. Remove the window or trim seal piece and install new putty or butyl tape under it. Then caulk if need be. Don't use DAP or other residential grade caulks. The generic recommendation is Dicor Lap Sealant on the roof, and Proflex RV caulk on the vertical surfaces. You can't go wrong with those. Of course there are equivalents.

There are plenty of videos of youtube on how to remove a window, or trim, etc. Neither is as scary as it seems. Windows are a piece of cake. Trim can be more involved, but it has to come off if it is leaking, unless you Eternabond over it. With as much rot as you've found, I'd say take the thing apart and fix it. Sorry. Or, sell it now. Actually, that's the best course of action, speaking from experience.

Take a look at the rotdoctor.com website. You may or may not be able to make use of his stuff at some point. I can attest that it is good stuff. And it does require a fumes respirator.

[DaHose]

I ended up in the same boat and had to rebuild the entire cannoneer. Lots of good technical and moral support round here. Post questions and we'll help as much as we can.

Jose

[chefdc1]

I'm going to have to rebuild the entire floor. I'll be asking questions in new posts. Oh boy, am I learning a lot about rv repair quickly. We just bought this, our first, two months ago!

[DaHose]

Sounds like an Eternabond job to me, chefdc1. The way to do it is to remove the trim, clean surfaces well, then apply the eternabond to the whole seam. Make sure you roll it well with your metal roller so that the edges squish out a little and really stick. Then put butyl rubber under the trim strip and screw it back down. That should hold for many years.

Jose

[EMD360]

This is the eternabonded corner five years after I applied it.

The bottom was repaired twice so the tape is wider and the metal is bent but it won't leak which is the important thing.
I used two strips of 2" tape and wrapped one over the edge and then the other over that. I also did the roof seams and all the lights including those pesky overhead lights. So that the only opening to the inside was for the wires and those are on the upper side so water would drip down and out.
I think eternabond is great stuff. It flexes enough so that no future cracks are possible and keeps the water out. But it takes some time to apply. I have to do the front edges and unfortunately I put off the job long enough that I found water inside after the snow and ice of November.

[Jim_Shoe]

I'm just throwing this out there.
I bought my 'C' new. It had to be ordered. When it came in. the dealer called me to look it over, but told me that they had work to do before letting me have it. They said the marker lights on the cab over are installed at the factory with power screwdrivers and its easy to create hairline cracks that leak. They removed the lights, checked for cracks (there weren't any) and resealed them. Over 10 years and no leaks. BTW, I only store some light weight stuff in the overhead. Nobody has ever slept in it.

[mikeleblanc413]

Following. When looking to purchase Winnie in 2011 my short list included an open cabover area so that it would be easy to track leaks. I only store light items and we have never slept in the cabover bunk.

[chefdc1]

Did a lot of digging around today...lots of rot! I'm going to have to rebuild the entire cabover bed. I think I tracked the leak(s) to the front seams. I cleared out all of the caulk on both sides of the trim, from roof all the way around, under cabover and back to house. Started getting dark so I couldn't reseal, but I covered everything with duct tape. I completely dried where the water looked to be coming in. I'm hoping that everything is still dry in the morning. There is supposed to be a shower so it should be a good test.
The plan is to reseal everything with a flexible, waterproof, non silicone caulk (DAP Clear). Now I'm wondering if I need to pull off the strip in the trim to check the screws.
Also, can I seal along the strip (inside the trim) with flexible caulk as well?
Should I be thinking about using eternabond, and if so, where? Under the trim? Over the trim?

[chefdc1]

Sprayed a hose all around and it looks like the seams in front are leaking. Bought some DAP Clear Flexible Sealant (Met a contractor at Lowes, said it was the best, sticks to everything, lasts forever).
Going to seal Everything!
Wish me luck.

[EMD360]

I have to hope we don't have rot. I had not noticed a leak from rain, but the first cold/snowy weather we had, I was running heaters inside because I hadn't winterized yet and the front had lots of icicles that hung off the cabover until it warmed up.
I was removing the bedding and noticed the wetness. Just in the corner on the floor--the sheets were wet there and the corner was black already--so I assumed it was the edge caulking. I put on some new caulking--I had some sikaflex left over, but still thought all winter without a thorough sealing would be a problem, so I bought a cover rated for snow and wind and put that on until spring.
I'm going to remove the metal edges and put eternabond on the corners. Then reinstall the edging with stainless steel screws and install some new trim. That is what I did to the two rear seams and it appears to work well. I also redid all the roof seams and openings with eternabond. I had bought the supplies for the cabover seams but didn't get to the project last summer.
Good luck with your repairs.

[chefdc1]

Thanks Jose. I just sent you a private message. I need help and as much info as I can get. I have to redo the whole thing! I tried to follow your link, but it wouldn't load completely.
I think I found the leaks, so I'm hoping to repair them today then start on the inside asap. I'm on vacation (luckily we planned on staying home!) For a few weeks, so I am hoping I can get it done.
Thanks for any and all advice.

[DaHose]

If the leak is around the window frame seal, then you need to buy some butyl tape and reseal the window frame to the outer shell. I used a white tape when I did my windows, but there is black too. Look on youtube for how-to videos.

Proflex RV is a product I see recommended all over (I have a tube in the parts box), but in pinch you could use a DAP brand sealant called Alex (acrylic latex). You can buy it at Home Depot or any other hardware store. It adheres really well to lots of different surfaces and is paintable. It comes in tubes for your gun, or in a pressurized, self dispensing metal can package. I keep a can and some extra Eternabond in the RV for emergencies.

Jose

[Travelcrafter]

what ever you do DO NOT USE Silicone OR Silicone based caulk! when I done my camper I used a product called Sickaflex on my side and raised seals, Dicor is another good product. for my windows around the glass I used a clear polyurethane I got from Lowe's It is crystal clear and it worked very well.My camper is a 78 Travelcraft and I have not found any leaks as yet. Lock-tight has some good caulk too that was recommended by an RV dealer just make sure not to use silicone it will not work.