I have a square brinkmann vertical smoker and I am thinking of covering the exterior with wood, putting a little pitched roof on top with a single smoke stack comming out to look like a chimney. I think it would help me maintain more consistant temps since so much heat is lost through the thin walls before it even gets to the top rack. It would also make for a more rugged smoker and look neat. At first I was just thinking plywood but now I think I will use 1x3 or 1x4 cedar. I would keep the original location of the bottom vents but cover the top ones and put a single stack on top in the middle pointing strait up, this would solve the problem of having a cross wind through the original top vents. Any thoughts on this?