Water Leak on Cab of Class C

Tioga Pat

New Member
I'm curious. Is there anyone who owns a Class C that has not encountered a leakage problem in the cab of a class C?
I thought that since I had someone caulk around all of the running lights (one of which had water in it) that my problem
would be solved. However, water is not coming from the running lights or the window since it has been sealed. Where else should we look for
the leakage problem? It seems like it is coming down the left side wall where the wall meets the bed platform. but no
indication of the wall being wet. Any information would be appreciated.

C Nash

Senior Member
Re: Water Leak on Cab of Class C

Welcome to the forum Pat. Have you check the roof good? Water can find the smallest crack. Ck all seems, AC, antenna and anything else up there. Could even be coming from the back and running down the chenel till it finds a place to come in. Water leaks can be the devil to find. Might try spraying water on just small sections at a time until you locate it. Good luck and let us know what you find.


Senior Member
Re: Water Leak on Cab of Class C

Tioga Pat-
The last two leaks (yes, there have been others) I have fixed were at the roof seam and at the awning bracket.


New Member
RE: Water Leak on Cab of Class C

Hey, TP

Just got done completely rebuilding my bunk on a '79 Tioga. Water leaks in at two main seams that I noticed. First, the front window. Not sure why this is such a persistent problem, because that bugger had been caulked and reseated before.... The second main point of entry seems to have been at the bottom seam of the left sidewall of the bunk. On the '79, there's a corner molding on the bottom edge of the outside bunk that catches water as it runs from the roof above. I've since purchased and installed a rain gutter at the roof seam and completely removed and resealed the corner beads all around the motorhome. I used rope caulk underneath, available at any local hardware store for a few bucks a roll.

BTW, once the bunk wood gets wet underneath, there's virtually no way for the moisture to get out. Pull the bunk bedding, any and all wood-framed bunk inserts (like night stands, drawers, etc, and put a space heater up there for a few days.

Anyhow, hope this helps. If you are smelling mildew and can push your finger through anywhere, I would suggest gutting the bunk and starting over. I did so, and am very happy with the results. I welded in new square tube-steel for a bed frame and laid 3/4 plywood over the top. Saved all paneling pieces I pulled off to use as stencils for the replacements to make things easier. Took two days of work, plus about a week of space heater to dry things out good. About a $120 fix in materials....

Hope you can avoid all that and find the leak in time!