Hello I am in the process of building a hearth for a tnc30 from overstockstove. I am building the wall shields using metal studs laying flat with two layers of cement board on top. Does anyone have any ideas if vent strips are made that can go across the top of the wall where the air space is? I would like something that looks a little better then just a gap on top of the wall showing the cement board and studs. Any ides are welcomed. Thanks.