Building the back wall for a wood stove install and why is it all the pictures I see of hearths built I don't see any space on the bottom or top where cement board or veneer for the back wall. I was advised on another post I'm still working thru to get it done right. New to the forum and asking for help!! Not looking to do it wrong. I'll install metal soffit vents and blend it in rather than a gap on top and bottom. Just a gap doesn't look right. The metal studs doubled up are secured to a plywood wall with liquid nails and decks every 12" next is 1/2" cement board.