I think it is pretty common, but it shouldn't be happening. You can have a bare piece of plywood outside in the rain and it takes about a year to delaminate. In fact i have a piece that has been sitting outside for over 2 years now and still hasn't delaminated. The plywood in the trailers is protected so should last longer even if there is a slight leak. I had my 2014 22fbs inspected when i noticed the delamination and the caulk was all fine around the windows, but I was still getting delamination under 1 window (3' x .5'). We could find no sign of water intrusion. It is 1.5 years old and Heartland would not cover the repair (I sent photos and now will be sending some of the window caulking). The only thing I noticed is that the factory only caulked the top of the windows, seems pretty stupid when the thing will sometimes be traveling 60mph in the rain. I would have and will caulk all around the windows now. I didn't before this because the factory obviously did not see a need to do so. Since it is only a little over a year old I am nervous that even though I fix this that it might start happening elsewhere. I live in Minnesota where temps go from 100 down to -30, and the side with the delamination is the side the sun hits in the summer. I am thinking either the glue was breaking down because of the temps, or there was not enough glue applied at the factory, and not water. Still working on it. I can handle this one because it is right where I wanted to mount a solar panel, so after fixing it should cover it and give the wall more support. But, if the delamination continues elsewhere i can't cover the trailer with solar panels. The reason i bought new was because so many older trailers had problems like this. Now i know I should have bought a used one.
