(E) ln the area for which a hearth extension is required (see Clause 5.3.6.3), the
joint between the wall face below the hearth and the hearth extension shall be
provided with a firestop of sheet metal.
5.3.6.6
A vertical face below a fireplace opening shall be of noncombustible material, shall
extend to the top of the hearth extension, and shall extend at least 8 in. (200
mm) on each side.
5.3.6.7
When tile veneer is used (25 mm or less) on the vertical face below a fireplace
opening, it shall
(A) be backed with a sound, dry, rigid plane surface consisting of masonry,
reinforced concrete, or cement plaster on metal lathe; and
(B) be applied to its noncombustible backing by means of full embedding in
Type M mortar or other approved means with ail joints filled.
5.3.9 Clearance of Combustible Material
5.3.9.1
Combustible material shall not be placed on or near the face of a fireplace within 6 in.
(150 mm) of the fireplace opening, except that where the combustible material
projects more than 1-1/2 in. (38 mm) from the face of the fireplace above the opening,
such material shall be placed at least 12 in. (300 mm) above the top of the opening.
Material below the opening shall conform to Clause 5.3.6.
5.3.9.2
Metal exposed to the heated interior of a fireplace, such as the damper control
mechanism or a built-in glass door, shall have at least a 2 in. (50 mm) clearance from
any combustible material on the face of the fireplace where such metal penetrates
through the face of the fireplace.
5.3.9.3
When a fireplace is equipped with heat circulating outlet ducts above the fireplace
opening, the distance from such a duct or metal duct grill to the combustible material
above shall beat least 12 in. (300 mm) where the combustible material projects more
th an 1-1/2in. (38 mm) from the face. Where the combustible material projects less
than 1-1/2 in. (38 mm), the distance between the combustible material and the duct
shatl be not less than 6 in. (150 mm).
REQUIREMENTS FOR THE HEARTH
EXTENSION
CLEARANCE FROM COMBUSTIBLE MATERIALS
Min. 6” of
noncombustible
6”
12”
Flush fireplace:
6” clearance between
the hearth and a
combustible material
Fireplace with a 1-1/2”
projecting shelf (or more):
6” clearance on each side and
12” clearance at the top
Flush heating grill
6” clearance
Heating grill recessed
1-1/2” behind the surface
12” clearance
Cantilevered
reinforced
concrete slab of 4”
tapered to 2” min.
Standard
hearth
2” min. Reinforced
concrete slab
Metal
fire shield
Elevated
hearth of
8” min.
Choice no1:
8” min
Grouted ceramic tile or
stone, 1” thick min,
over a metal sheet of
0.5 mm
Metal
fire shield
Choice no 2:
8” min
4”
2”
min. 6” of
noncombustible
Min 12”
&
Page 26
REV. 2014-11
APPENDIX 1 (Con’t)
16”
18”
18”
