Wall shields up! I used hat channel from a drywall shop. It's 7/8" high - close enough - I really did not need the shield for clearances, I just like to be overly careful and thought it would look cool. So 7/8" hat channel attached to the drywall with metal wall anchors, then 1/2 Durock screwed to hat channel, then used high temp silly-cone to glue on tin tiles. I used drywall "J" channel to border the edges - it's just a metal edge that snaps onto 1/2" drywall. It fit really tight over the Durock and the tin, so I didn't even have to glue it. Used hi-temp rust-o-leum spray paint to get it flat black.