Hello, my wife and I got ourselves a 1991 Toyota Itasca. It has some water damage in the over-the-cab sleeping loft and in the bathroom (in the back). We started removing the affected areas but we are looking for any advice the forum might offer to make the job more successful. In that spirit, I'll outline our plan and maybe you can warn of us some pitfalls, offer critiques, or advise on materials we should use.
In the over-the-cab loft, the existing material on the flat section and the walls appears to be some styrofoam sandwiched between some wood veneer attached with adhesive to the fiberglass skin (the skin being the outside of the motorhome). We are removing that and scraping the wood veneer off of the fiberglass with a sharpened wood chisel. We are still looking at what material we should use as replacement. I am surprised that the flat area of the loft is just veneer and foamboard, since it needs to be able to support the weight of one or two people. I've seen on some other posts the suggestion of using marine plywood, but my concern with that would be the lack of insulation.
Also in the over-the-cab loft, on the curved front section where the horizontal window is, we plan on gutting and replacing the styrofoam insulation that is there. Is this necessary?
Finally, there is the obvious necessity of finding and fixing the leak that has allowed the water to breach the sealed exterior so that it doesn't just recur in the future. I'm suspecting the window or the seam between the side and roof/front of the the motorhome meets. However, I guess it isn't really important to determine where the leak is - instead, we should just shore up both areas. I assume that this would require a decent amount of silicone caulking? Is it usually necessary to remove the window and reinstall it?
To avoid making too long of a post, I'll leave it there for now. Any help is appreciated. I will attach a few pictures and will add more as requested. Thanks!