Fireplace Installed Flush On The Floor And Hearth Extension Raised To Bottom Of Firebox Opening - Heatilator BIR42-B Installation Manual

1. Fireplace Installed Flush on the Floor and
Hearth Extension Raised to Bottom of Firebox
Opening
Non-combustible fl ooring a minimum of 20 in. (508
mm) in front of and 12 in. (305 mm) to each side of the
fuel opening is required.
The hearth framing must be constructed of non-com-
bustible materials (such as metal framing or equivalent
material) and placed on two HX4s and 1/2 in. Durock,
or equivalent material. Refer to Figure 7.5.
When creating the platform, allow for the thickness
of the non-combustible fi nishing materials.
Seal gaps between the hearth extension and the front
of the fi replace with a bead of non-combustible sealant
or grout.
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.
Continuous,
non-combustible sealant
Durock Tile, stone or other
non-combustible material
1 in. Micore or
equivalent insulation
(see Table)
Floor constructed of wood or
other combustible material
Figure 7.5 Hearth Extension Construction
30 Heatilator • Birmingham 42-B Installation Manual • 4059-715 • Rev C • 2/14/13
Protective
Metal Hearth
Strip
*
*
* 2 in. (51 mm)
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.
Continuous,
non-combustible sealant
Tile, stone or other
non-combustible finishing
material
20 in. minimum
Hearth Extension
Protective Metal
Hearth Strips
1 in. Micore or
equivalent insulation Non-combustible
& 1/2 in. Durock Framing Material
Figure 7.6 Raised Platform Hearth Extension Detail
Noncombustible
Framing Material
Figure 7.7 Raised Platform Hearth Extension-Framing
Non-combustible
Finishing Materials
Figure 7.8 Raised Platform Hearth Extension-Finishing
Bottom of
fireplace opening
Platform must be built
to raise the bottom of
the fireplace opening
to the level of the
desired hearth height.
Floor and platform constructed of
wood or other combustible material
HX4 or
equivalent