16
Majestic Fireplaces
®
SR/SC Series
■
9. Hearth Installation
A hearth extension is required to protect a combustible
floor in front of the fireplace. Refer to Figure 23 for
minimum dimensions and mounting detail.
Note: Hearth Extension must not cover the air
inlet opening of a fireplace.
The hearth extension described in Figure 23 must be a
durable non-combustible material with a minimum
(total) Rt value of 1.09; see Figure 24 for examples.
The overall height (above a combustible floor), depth
and width must be as indicated, with the extension
centered to the fireplace opening.
The top of insulation must be covered with a non-
combustible decorative covering or a piece of .018”
minimum sheet metal, to protect hearth extension
material. (Fig. 23)
Secure the hearth extension to the floor to prevent
shifting, using trim molding or other similar means at
three (3) outer edges. Seal crack between the fire-
place hearth and hearth extension with a non-combus-
tible material. (Figs. 23 and 25)
WARNING: HEARTH EXTENSION MUST BE
INSTALLED IN ACCORDANCE WITH FIGURE 23
AND MUST NOT COVER THE BOTTOM FRONT
OPENING OF THE CIRCULATING MODEL.
Alternate noncombustible materials may be used
providing the (total) thermal resistance (Rt value) of
the alternate material employed is greater than or
equal to R = 1.09. Thermal resistance (R) or thermal
conductivity (K), may be obtained from manufacturer
of the material. Factors are related by the formula K =
1/R.
T = given thickness
R = thermal resistance for a given thickness (T)
K = thermal conductivity
Noncombustible material with a lower R value may be
used, provided thickness of material is sufficiently
greater to maintain an equivalent (total) thermal
resistance (Rt).
FP594
Fig. 23 Combustible side wall protection and hearth extension dimensions.
Minimum Wall Clearances
WITH
Noncombustible
Surround Facing
WITHOUT
Noncombustible
Surround Facing
Minimum Hearth Extension Dimensions
(for On-Site Construction)
G
H
G
J
Seal cracks
between the
fireplace
and hearth
extension with
noncombustible
material
Safety strips
must overlap
¹⁄₂
" minimum
May install
noncombustible
decorative
covering
OR .018" min.
sheet metal
FIREPLACE
HEARTH
COMBUSTIBLE
FLOOR
MINIMUM
INSULATION
VALUE "R"
4" MIN.
FIREBOX
OPENING
A - Min. clearance
to combustible
perpendicular wall
B - Min. clearance
to combustible
perpendicular wall when
using noncombustible wall shield*
SIDE
WALL
SIDE
WALL
F**
C**
E
E
D
4" BRICK
(Example material)
Combustible material permitted within shaded area.
* Noncombustible wall shield requires 1" Majestic EH2416
insulation (minimum R Value = 1.85) between decorative
noncombustible rigid covering and combustible wall.
Minimum height and width is 40" x 40".
** Dimension/degree of angle will vary depending on thickness
of noncombustible surround facing.
4"
Shaded area starts
1/2" away from
edge of unit.
A
B
C
D
E
F
G
H
J
SR/SC36
16"
12"
48
°
41
°
18"
14"
7
³⁄₄
"
16"
48"
406mm 305mm
457mm
356mm 197mm 406mm 1219mm
SR/SC42
20"
12"
42
°
35
°
18"
14"
11
¹⁄₂
"
20"
61
¹⁄₂
"
508mm 305mm
457mm
356mm 292mm 508mm 1562mm
