I'm planning on putting a 6ft X 3ft hearth extension below the new Regency I3100 insert. The raised hearth will be granite on top of the existing 3" steel angle / concrete filled raised hearth.
My installer suggested that if I use a metal barrier above the sub-floor that I could use 1/4" wonderboard under the slate tiles I am installing. So it looks like this: Sub floor (plywood), galvanized steel (same gauge as joist liners) nailed to sub floor, 1/4 wonderboard screwed thru the steel into the sub floor, then the tiles installed using standard thinset. The tiles are 3/8" thick slate. He saus becasue it's a metal "shield" the 1/2" cement board requirement is not needed. The raised hearth sits approx 12" above the floor.
The manual says that "thermal floor protection is not required if the unit is raised 3.5" minimum off the floor. However standard ember floor protection is required. It will need to be a non-combustible material that covers 18" in front (Canada) and 8" to the sides." Since the insert is about 16" off the floor, the ember protection applies yes?
Sound right?
My installer suggested that if I use a metal barrier above the sub-floor that I could use 1/4" wonderboard under the slate tiles I am installing. So it looks like this: Sub floor (plywood), galvanized steel (same gauge as joist liners) nailed to sub floor, 1/4 wonderboard screwed thru the steel into the sub floor, then the tiles installed using standard thinset. The tiles are 3/8" thick slate. He saus becasue it's a metal "shield" the 1/2" cement board requirement is not needed. The raised hearth sits approx 12" above the floor.
The manual says that "thermal floor protection is not required if the unit is raised 3.5" minimum off the floor. However standard ember floor protection is required. It will need to be a non-combustible material that covers 18" in front (Canada) and 8" to the sides." Since the insert is about 16" off the floor, the ember protection applies yes?
Sound right?