Stratford
Fireplace Installation and Operation Manual
__________________________________________________________________________ 37
Thermal Characteristics of Common Floor Protection Materials*
MATERIAL
CONDUCTIVITY (k)
PER INCH
RESISTANCE (R) PER INCH
THICKNESS
Micore
®
160
0.39
2.54
Micore
®
300
0.49
2.06
Durock
®
1.92
0.52
Hardibacker
®
1.95
0.51
Hardibacker
®
500
2.3
0.44
Wonderboard
®
3.23
0.31
Cement mortar
5.00
0.2
Common brick
5.00
0.2
Face brick
9.00
0.11
Marble
14.3 – 20.00
0.07 – 0.05
Ceramic tile
12.5
0.008
Concrete
1.050
0.950
Mineral wool insulation
0.320
3.120
Limestone
6.5
0.153
Ceramic board (Fibremax)
0.450
2.2
Horizontal still air** (1/8")
0.135
0,920**
* Information as reported by manufacturers and other resources.
** For a 1/8" thickness. You cannot «stack» horizontal still air to accumulate R-values; you must separate
each layer of horizontal still air with another non-combustible material.
6.2.4
MINIMUM HEARTH EXTENSION REQUIREMENTS
The hearth extension floor area must extend at least 16"
(41 cm) in front of the hearth
(A)
and at least 8" (20 cm)
on each side of the door opening (
D
). The joint between
the hearth extension and the fireplace hearth needs to
be made of non-combustible material such as sheet
metal (not included).
CLEARANCES
A
16" (406 mm)
B
41.5" (1054 mm)
C
8" (203 mm)
