Finishing, Hearth Extension | Hearth and Home Technologies BIR50-B

12 Finishing

A. Non-combustible Materials

•Materials which will not ignite and burn, composed of any combination of the following:

-	Steel	-	Iron
-	Brick	-	Tile
-	Concrete	-	Slate
-	Glass	-	Plasters

•Materials reported as passing ASTM E 136, Standard

Test Method for Behavior of Metals, in a Vertical Tube Furnace at 750° C

B. Combustible Materials

•Materials made of or surfaced with any of the following materials:

-	Wood	-	Compressed paper
-	Plant fibers	-	Plastic

•Any material that can ignite and burn; flame proofed or not, plastered or un-plastered

C. Hearth Extension

WARNING! Risk of fire! High temperatures, sparks, em- bers or other burning material falling from the fireplace may ignite flooring or concealed combustible surfaces.

•Metal hearth strips MUST be installed (Section 7.C.).

•Hearth extensions MUST be installed exactly as specified.

•You MUST use a hearth extension with this fireplace.

•This fireplace has been tested and approved for use with a hearth extension insulated to a minimum R value of 2.32.

•The hearth extension material MUST be covered with tile, stone or other non-combustible material.

•Manufactured hearth materials will usually have a published R value (resistance to heat) or k value (conductivity of heat). Refer to the formula in Table 12.1 to convert a k value to an R value,

•Refer to Table 12.2 for hearth extension insulation alternatives.

12in.

(305 mm)

	50 in.	12 in.
	(1270 mm)
		(305 mm)

Table 12.1

R = 1/k x inches of thickness

74 in.

(1880 mm)

(R value of hearth must be equal to or greater than 2.06)

20 in. (508 mm) Minimum

Figure 12.1 Standard Hearth Extension Dimensions

Table 12.2

Hearth Extension Insulation Alternatives-Total minimum R Value must equal 2.06

	k per inch	R per inch
Material	thick	thick	Minimum thickness required
Hearth & Home HX3, HX4	0.49	2.06	1 1/2 in. (38 mm)

USG Micore 300™	0.49	2.06	1 in.(25.4 mm)
USG Durock™ Cement Board	1.92	0.52	4 1/2 in. (114 mm)
Cement Mortar	5.0	0.20	11 5/8 in. (295 mm)

Common Brick	5.0	0.20	11 5/8 in. (295 mm)
Ceramic Tile	12.50	0.08	29 in. (737 mm)

Armstrong™ Privacy Guard Plus	0.46	2.18	1 1/2 in. (38 mm)
Marble	14.3 to 20.0	0.07 to 0.05	33 to 46 1/2 in. (838 to 1181 mm)

Heatilator • Birmingham BIR50-B • 4059-682C• 8/12