Do you have a Wood/Pellet Stove Insert with a Raised GRANITE Hearth?
Anyone else have a wood or pellet stove insert (the kind that protrudes out of the fireplace) with a raised granite hearth?
I have a 1970 era fireplace, with chimney on an exterior wall. About 48" wide 36"+ tall.
I have a stove insert with standard black steel mantel/trim.
13" of the stove is behind the trim, and 12" in front. My wife does not like brick. We removed all brick protruding into the room. The bottom of the fireplace is about 14" above the floor of the room.
Now, I am about to build a raised granite hearth (standard 24" depth slab, 3/4" thick).
About 12" of the stove will rest on the granite slab.
Challenge 1: Stove is 400+ pounds (180+ kg).
Challenge 2: Manufacturer recommends Hearth pad with R2.5 or greater.
Seems like I must use concrete/brick blocks underneath the single piece granite slab, due to variable linear expansion characteristics of other materials in comparison to the granite slab. OR, perhaps the granite slab rests on the supporting frame without having been glued/cemented to it, using something like Ditra on top of cement board, on top of plywood?
Challenge 3: Regardless of support for granite slab, heat reflection from the stove might cause the granite to crack. Perhaps trimming a piece of aluminum flashing and stove board (e.g. Imperial) to precisely fit underneath the stove, above the 12" of granite directly underneath the stove might provide sufficient shielding to prevent the heat from cracking the granite?
Someone else suggested Ditra underlayment, but Ditra is composed of polyethylene, which melts at 85 Celsius / 185 Fahrenheit. Perhaps using Thermix or HomeSaver chimney liner insulation (vs. thinset) mortar might help keep the Ditra cooler. A 7 foot long slab of granite hearth ought to absorb and reflect all heat emitted by the stove insert without heating up too much.