Is this a cabover leak

[PartyOf_Five]

We recently noticed a brown line descending from the cabover, and along the caulk line and aren't sure where to start troubleshooting. Some of it came off with rubbing compound, and didn't re-appear - even though we've had heavy rains recently. We haven't gone on the highway since we saw this though.
Thanks for your ideas & expertise!

[Mich_F]

crasster wrote:
Definitely need a pic.

Click on the OP's profile - click is there. 😉

[crasster]

Definitely need a pic.

[fitznj]

any brown residue is an indication of a leak - we had a similar problem on our camper. I kept seeing a brown stain at the bottom but NO soft spots on the outside
and no stains on the inside; I think water got between the outside fiber glass sheets and the wood.

Either way it's not a good sign - you may want to fix it asap

[ksg5000]

Likely a leak but probably not a typical cab over leak associated with Class C's. If it were me I would spend a $100 and have the rig pressure tested - that should identify the actual source of the leak and you can figure out it you want to fix yourself or pay someone to fix. Finding the source of leaks can be a real PIA in RV's - lots of potential sources.

[Mich_F]

The wall behind the cab is the transition wall. They are not really constructed like houses. You most likely have your wallpaper (which is probably paneling)and a plywood or particle board behind that, with your exterior fiberglass on that. The sides of the house would be built differently.Yours are probably the wallpaper/paneling on the inside with foam behind that, then door skin, with the fiberglass sides attached to that. Your house framing is probably aluminum.

[PartyOf_Five]

What are you referring to as the transition wall? We haven't noticed anything in a year, but I'll check inside the storage cabinet, which would be the inside of that wall too. What's behind the wallpaper - are these constructed like houses, i.e. drywall equivalent, with wood/ metal studs behind, then the structural outer layers?

[Mich_F]

That is probably from a leak. If not in the bedboard, then it's in the transition wall. Any signs of a leak on the inside ? Any soft spots or stains on the bedboard or that wall ?

You might want to remove the vinyl insert in that vertical molding, remove the screws holding it on, remove the caulking on the sides of it, and take it off. That would give a glimpse of what that corner looks like, under the trim.

[PartyOf_Five]

Couldn't figure out how to add a pic, so I finally inserted it as my Rig Picture in my profile. Thanks.