Desa VS42H(1), S42R Fireplace Installation, WARNING Hearth extension, Continued, Hearth Extension

FIREPLACE INSTALLATION

Continued

Note: For outdoor installations, the fireplace en- closure must allow for adequate drainage and fresh air ventilation. It is recommended that a sealed, corrosion resistant catch pan with provision for drainage be installed under the fireplace within the fireplace enclosure.

HEARTH EXTENSION

A hearth extension projecting a minimum of 16" in front of and a minimum of 8" beyond each side of the fireplace opening is required to protect combustible floor construction in front of the fire- place. Fabricate a hearth extension using a material which meets the following specifications: a layer of noncombustible, inorganic material having a thermal conductivity of K=0.84 BTU IN/FT, HR. F (or less) at 1" thick. For example, if the material selected has a K factor of 0.25, such as glass fiber, the following formula would apply:

0.25x 1.0" = 0.30" thickness required

Thermal conductivity "K" of materials can be obtained from the manufacturer or supplier of the noncombustible material. If the hearth extension is to be covered, use noncombustible material such as tile, slate, brick, concrete, metal, glass, marble, stone, etc. Provide a means to prevent the hearth extension from shifting and seal gap between the fireplace frame and hearth extension with a non- combustible material (see Figure 3).

WARNING: Hearth extension

is to be installed only as shown

in Figure 3.

Seal Gap

Fireplace Front

MANTELS
A mantel may be installed if desired (see Figure
4). Woodwork such as wood trims, mantels or
any other combustible material projecting from
the front face must not be placed within 12" of
the fireplace opening. Combustible materials
above 12"	and		projecting more than 1		1	/2" from
the fireplace must not be placed less than 15"
from the top opening of the fireplace (NFPA STD
211, Sec. 7-3.3.3).
Mantels or any other combustible material also
may come up to the side edge of the black metal
face of the fireplace just as long as the projection
from the front face fall within the limit shown in
Figure 4.
				Combustible
	12	1	/4" Ref.	Material
				Safe
6"				Zone for
Ref.	33°			Projection of
				Combustible
	3" Nom.			Materials
15" Min.	1
	1	/2" Max.
12"	Min.			Upper
				Section of
				Fireplace
	Fireplace
	Opening
Top View of Fireplace
				FIREBOX
8.0"

Ember Protector

Fireplace Front

Raised Hearth

Ember Protector

Fireplace Front

Elevated

Hearth

Extension

Seal Gap

	2" Max.
SAFE ZONE	3.0"
33°
Min. to
Perpendicular	Combustible
Side Wall
	Material Must
12"
	Not Overlap
	Front Face
Figure 4 - Mantel Clearances to
Combustible Material

Ember Protector

Figure 3 - Hearth Extension

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