Harman Stove Company HB 38 DV Installation And Operating Manual page 14

Only For Qualified Installers
Installing fireplace in a wall with an arch face, ceramic tile facing,
and a face mantel.
Noncombustible
Noncombustible material such as Dura-rock must be used
as facing on the front of the fireplace cabinet.
Ceramic tile, marble or other decorative noncombustible
material may be used in front of the Dura-rock. The total
thicknes for all layers of facing material may not exceed
one inch.
INSTALLATION
A one inch space under the front edge of the fireplace
allows room for hearth material. Hearth material that is
thicker must be compensated for by raising the fireplace the
proper amount.
14
1 inch thick