Brian even though I have never installed it on walls but I have done so on floors IK would think that you would still have to put plywood on the frame work of the bus first and sqaure up the walls where as they are probably somewhat bowed now. You will never get T&G plank to bend unless it's really thin and I haven't seen any like that! Keep in mind that when you plywood the walls and then install T&G over it, you will lose space in the width of your interior. make sure you have plenty of room before proceeding. 3/8 ply minumum on walls and 3/4" T&G means roughly losing over 2 inches total. I know it doesn't sound like much but after you start putting furniture in place, it starts closing in real quick!
The 5/16" stuff is what I am planning to use if cost is feasible. I am thinking of running horizontal as the side walls running vertical and the ceiling running the length of the bus might look funny. I have everything stripped out of the bus including the interior panels basically down to the steel frame. Dina covered the steel frame with sheetmetal on the inside.Brian Elfert
Brian, This is what we used for wainscoating in our house as well as our bus and the ceiling in the bedrrom and bath of the bus. In our house it was glued to the drywall and trim nail used to hold it in place until the glue set up. In the bus we put 1/2" plywood on the walls, then put a few globs of PL200 polyurethane adhesive on the back of each piece. A couple 5/8" brads from the air nailer holds it place until the glue set up. Ceiling was done the same way except attached to 3/8" plywood. We carefully put the brads into the edge of the tongue so no nails show on finished surface. You can see a few photos of our bus at http://members2.clubphoto.com/jack217421 Just look for the Orange Blossom Special II albums (volumes 1-3) Hope this helps, JackPS: if you plan to stain the wood, do so before installing. This will prevent any unstained lines in the joints if the wood should shrink after installation.
Brian, Thanks for the compliment. The ceramic tile on the kitchen and bathroom countertop/backsplash was attached to the plywood wilth standard wall tile adhesive. The grout was mixed using