We have a screened-in porch that runs the entire length of the back of our house. Part of it goes behind the kitchen so we are enclosing that half of the porch and making a mudroom/laundry room. I am wanting to put 4' x 8' sheets of material that looks like beadboard. Kind of like the old wooden paneling. Do we have to put the drywall on first and put the other material on top of that or just put the beadboard up without it. Sorry if this sounds silly but we are new at doing this kind of thing. I don't want to drywall every wall if it is not necessary but it seems that if we don't, the room will be much colder in the winter than it would be with drywall. We live in northern IN.