We are trying to rework a heat shield behind our wood stove. It previously was corrugated steel that was attached directly to the drywall and that worked fine, but I want something pretty. The clearances are currently appropriate and have about 1.75” to work with in replacing the steel. I want to use a brick veneer tile and and wondering if I can attach Hardi cement board directly to the drywall or if we have to remove the drywall and put the cement board in its place. The clearances will work fun with attaching it to the drywall, but I don’t know if the heat will just pass through to the drywall. Any advice is appreciated!