I am installing a spa in my spare bedroom. This is not a hard wired type, you just fill it and plug it in. My son as well as others are telling me that this will cause much problems in this bedroom. I thought that I could just apply green board over the present drywall, and paint that with kilz, and that would make the room mildew resistant. I do not want to put the spa outside, as I live in New Jersey, and I just can't see relaxing in this nice hot whirlpool in 8 degree winter weather, running in and out of the cold. Please give me some advice. My funds are limited, so major renovations such as glass block, or tile, is a little costly. I also thought of applying formica with adhesive to the present drywall walls.