Table of Contents
Advertisement
WARNING
Fire Risk
•
Metal hearth strips MUST be installed.
Sparks or embers may ignite fl ooring.
Metal Hearth Strips
Metal hearth strips are placed 2 in. (51 mm) under the front
of the fi replace and must extend beyond the front and sides
of fi replace opening by 2 in. (51 mm). The metal strips must
overlap by 1 in. (26 mm) minimum.
Figure 8.2
Place Metal Hearth Strips
Hearth Extension
If not using an HX3 or HX4 hearth extension, refer to Sect.
A and Table 8.1 for substitute material.
HX3 or HX4
Figure 8.3
Hearth Extension, HX3 or HX4
Heat & Glo • RH-36/RH-42 • 4044-153 Rev S • 06/07
The hearth extension must be covered with non-combustible
materials as illustrated below in Figures 8.4 and 8.5.
•
Non-Combustible Materials
Material which will not ignite and burn. Such materials
are those consisting entirely of steel, iron, brick, tile, con-
crete, slate, glass or plasters, or any combination there-
of.
Materials that are reported as passing ASTM E 136,
Standard Test Method for Behavior of Materials in a Ver-
tical Tube Furnace at 750° C, shall be considered non-
combustible materials.
•
Non-Combustible Sealant Material:
Sealants which will not ignite and burn; Rutland, Inc.
Fireplace Mortar #63 Rutland 76R, Nuflex 304, GE
RTV106 or GE RTV116 (or equivalent).
4 in. (102 cm)
minimum
HX3 or HX4
covered with
non-combustible
facing
Figure 8.4
Hearth Extension
High temperature
(300°F min.) continuous,
non-combustible sealant
HX3 or HX4
Hearth Ext
Tile, stone or other
or equivilent
non-combustible material
insulation
(see Table below)
Floor constructed of wood or
other combustible material
Figure 8.5
Hearth Extension Detail
WARNING
Fire Risk
•
Hearth extensions must be installed
exactly as specifi ed.
High temperatures or hot embers may ignite
concealed combustibles.
See Figure 5
for detail
Fireplace
Opening
4 in. (102 mm) min.
2 in. (51 mm) of the Protective
Metal Hearth Strip is required
under the front of the fireplace
29
Advertisement
Table of Contents
