hi BFSOAB69.
have to agree with the prof, on this one. :cheer:
there is a couple of things one might not expect, a leak may or may not be from where you think it is, and once it has leaked, the damp will still be there doing damage until it completely dries out, if it's stuck inside the walls with little ventilation the time span can be considerable.
I will tell you a little story of damp, I had a Fleetwood that was a few years old, it showed all the hallmarks of leaking windows, damp sill and spongy wallboards under the windows, so one weekend I decided to remove the windows and reseal them, [first mistake] as it removed what waterproofing there was on the outside.
took all the first day to get the screws out as they were rusted in, removed the windows and found the the frame rotten, so the windows could not go back in,
had to do the window frame, so out came the front bunks and front wall boards, once out I found the wood above the window was soaked [so it was not the window leaking] must be the front join from roof to front panel.
as the front section was curved the front roof lining had to be taken out, [end of weekend] taped some plastic over the window opening till next weekend.
next weekend it rained all day saturday, in way this was a good thing as I could see water running down the roof panel on the inside, I took off the front roof section, and the top rail was wet through ah it must be the front rail. no it cant be because the water was further back, took out the next roof section, still wet, took down all the roof sections in the van.
then I found the leak :lol: it was the roof light that was leaking.
further back it was dry, the van had a sloping roof from back to front so all the water ran forwards from the roof light, down the front of the van.
the roof light had to come out [with rusty screws of course] and a new one fitted, once I had repaired the frame, and fitted the new light, I could not do anything until the frame of the van dried out took 4 weeks without front windows.
in all a two month job to complete most of the front fame had to be replaced all the wall boards and ceiling and part of the front floor, all through a leaking roof light that was far away from the signs of damp around the front windows.
water can travel a long way if left unchecked, but without stripping the whole lot one never really knows where it is getting in,, just my experience but not uncommon with damp issues..