Damp moldy spots on walls

[Seangie]

Hey All-

I have some damp moldy spots on my interior walls.  They are in different areas of the bus - Front , middle, back but all are at the same exact location on the wall.  Right below the bottom of the frame where the windows would go.  The bus was garage kept out in western Carolina before I bought it and unfortunately I have had to keep it outdoors. 

I have pulled the 1/4" painted ply off and sprayed the bus with a hose, been inside the bus during a good soaking rain and it has been completely dry.  I cannot find any leaks.  We live in coastal carolina where it gets pretty humid during the days (and some nights) and my assumption is that the frame is sweating and the water is leaking down the frame and out the seam between the pieces of plywood.  I am going to replace the walls with sealed/polyeurathaned wood or some type of plastic/composite that is mold resistant. 

I wanted to ask all of you  first what your experience was and if you have any suggestions to fix/prevent.  I am not worried so much about the walls getting damp as I am about the mold forming.

Figured you Florida Folk might have more experience with this as opposed to the Phoenix crew

Thanks in advance for all yout ideas and suggestions.  Ill post some pics tomorrow.

-Sean

[Busted Knuckle]

Sean,
While I'm of no help with this problem, I was looking at the pictures of your bus.

It looks very familiar to me. Is that by any chance Tom & Karen's old Eagle?

  BK 

[Oonrahnjay]

(snip) I wanted to ask all of you  first what your experience was and if you have any suggestions to fix/prevent. 

    Sean, I'd only suggest that you carefully look at everything above the wet spots.  It's not uncommon for a leak way high up (even up in the roof or at the roof/side join) to cause water to run down inside somewhere.  When it reaches some place like a bulkhead or a horizontal strut, it will puddle and find a way to leak out there.  In this circumstance, it is a leak but the real leak is nowhere near where you see it.  So this is something that needs to be considered.  Of course, the issue of condensation or "sweating" is an important one, too.  I'm afraid that you've got a big job ahead of you. 

[Ed Hackenbruch]

Put a dehumidifier in there for a few days and see if that helps get rid of the moldy spots?  (from an Az person)

[luvrbus]

Check all the window drains,check the window frame chalking the stuff dries out and leaks,check the drip rail above the windows it has a rubber gasket and screws,check the lights then check all rivets at the seams on the roof for seals leakage and tightness that's about it LOL  

You do have a job ahead of you I have a protimeter meter I will lend to you if you don't find the leak just promise to return it or you can purchase a cheap 1 at HF or Northern Tool it will help

good luck

[Seangie]

Is that by any chance Tom & Karen's old Eagle?

BK - You win a Prize!  Yes - It was Tom and Karen's old coach.  He's moved on to Prevost world.

you carefully look at everything above the wet spots

Bruce,  I have looked inside and out...The walls have been pulled down so that there is only frame and insulation.  Everything is completely dry.  We had 2 days of rain last week and there was not even a damp spot anywhere on the frame behind the walls.  This is why I am thinking sweating.  This is also happening in various places around the bus, not just one location.  You'll see that its on both sides of the bus in a couple of different places and the damp spots are in the same exact place in each spot, right below the seem between the 1/4" plywood under the frame of the windows. There was a paper backing behind a vinyl wallpaper and I think the lack of breathing trapped the moisture behind the wallpaper in the paper backing and it never dried.

You do have a job ahead of you I have a protimeter meter I will lend to you if you don't find the leak just promise to return it or you can purchase a cheap 1 at HF or Northern Tool it will help

Cliff - I am sending you a PM.  I have no idea how I would use one of those to find leaks in the frame and it really doesn't need to be a discussion here.

See the pics below of what I am talking about.  Also some bonus pics of a bus HB industries has on their lot.  It's currently owned and in use but is really pretty and all original in the drivers cockpit.  Even the original coin box.  I had the opportunity to visit them in CA last week and it was quite a treat.  Those guys do some amazing body work.

Thanks Again.

-Sean

[Oonrahnjay]

(snip) Bruce,  I have looked inside and out...The walls have been pulled down so that there is only frame and insulation.  Everything is completely dry.  We had 2 days of rain last week and there was not even a damp spot anywhere on the frame behind the walls.  This is why I am thinking sweating.  This is also happening in various places around the bus, not just one location.  You'll see that its on both sides of the bus in a couple of different places and the damp spots are in the same exact place in each spot, right below the seem between the 1/4" plywood under the frame of the windows. There was a paper backing behind a vinyl wallpaper and I think the lack of breathing trapped the moisture behind the wallpaper in the paper backing and it never dried. (snip)

     I see what you're talking about and, now that I've seen the photos, I agree with you.  But the spots are right on the level of the bottom of the window frame or below the window frame drains.  Both these spots are funnels for water dripping down the side of the bus (particularly if there are leaks around the window frame).  All you can do is investigate and -- while I'd be cautious about leaks around or associated with those windows -- it's looking like you do have a sweating issue.  And it's about to get really humid down here in southeastern NC.

     Good luck with it!   BH

[luvrbus]

It could be condensation but I doubt it check your belt-line strip also if anyone has replaced any of the rivets with pop rivets they will leak

good luck

[Scott & Heather]

Ditto what cliff said Sean. Pop rivets leak big time. Don't ask me how I know, suffice to say we went through hurricane Irene in the coach and found out the pop rivets do leak :-/ anyway could be that or maybe sweating and condensation creeping up the screws holding your wall material? Screws that go through the wood and into the frame will condense and sweat.


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