i have a brick fireplace and will be attaching a wood mantle.

we want to apply marble or granite sheets to the brick face of the fireplace
(the exposed parts to the inside of the mantle).

looking inside the fireplace, you'd see the white firebricks; the ends of
the outside layer of the brick; and then the finished side of the vertical
piece of marble or granite.

those end pieces of brick - leaving them as is would reveal that this is
basically a remodel of marble over brick.

it was suggested that we leave a 3/8" reveal when we attach the
marble/granite (meaning the marble would stick out beyond the brick by 3/8")
and then fill in that space (from the reveal angled back to the white
firebrick) with a layer of heat resistant furnace cement (we'd add some
texture by adding sand to it). we were told the color would basically match
the firebrick and would be a cleaner look than the old red brick.

is this something that's often done? does it make sense? thanks in
advance.

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