Outdoor Lifestyles by Hearth & Home Technologies Inc. • 4070-300 Rev C • 4/11 23

D. Raised Hearth Extension Framing

The hearth framing must be constructed of non-combustible

materials (Figure 12.2) and placed on 1/2 in. Durock and 1

in. Micore (or equivalent material) (Figure 12.4). When cre-

ating the platform, allow for the thickness of the non-com-

bustible nishing materials (Figure 12.5).

IMPORTANT! Hearth extension design must be determined

before installation of replace.

* 2 in. (51 mm)
Continuous,
non-combustible sealant
Tile, stone or other
non-combustible material
Floor constructed of wood or
other combustible material
1 in. Micore or
equivalent insulation
(see Table)
Fireplace
Protective
Metal Hearth
Strip
Durock
*
*
Floor
Non-combustible
Framing Material
Non-combustible
Finishing Material
Protective Metal
Hearth Strips
1 in. Micore or
equivalent insulation
& 1/2 in. Durock
Bottom of
fireplace opening
Note: The bottom of the fireplace opening is 3-3/4 in. (95.3mm) above the bottom of the fireplace. Finished hearth must NOT extend above this level.
Platform must be built
to raise the bottom of
the fireplace opening
to the level of the
desired hearth height.
20 in. Min.Hearth Extension

Non-combustible

Framing Material 1 in. Micore or

equivalent insulation

& 1/2 in. Durock

Non-combustible

Finishing Materials

Figure 12.3 Raised Platform Hearth Extension Detail
Figure 12.4 Raised Platform Hearth Extension-Framing Materials
Figure 12.5 Raised Platform Hearth Extension-Finishing Materials
Figure 12.2

Hearths should slope away from the front of the replace

and chase at 1/8 in. to 1/4 in. per foot. Spark strips must

be on top of any combustible hearth materials used for

moisture management.