16
M400BFC Balanced Flue Heat-Circulating Fireplace
87D1505
Side Wall Protection
Adjacent combustible side walls that are within mini-
mum dimensions shown in Figure 24 of the fireplace
opening must be protected with MHSC Wall Shield
Model SP40 or a specifically built wall shield described
in Figure 18.
The special wall shield design described in Figure 18 is
an alternate method of adding protection to side walls
and can be used in place of the SP40 with the same
wall clearances specified for the SP40. Rt must =1.85
minimum.
Examples of wall shield insulation:
1. Manville - CERAFORM 126, K=.27,
1/2 inches thick
2. EH2416, K = .458,
1 inch thick required.
Hearth Installation
A hearth extension is required to protect a combustible
floor in front of the fireplace. Refer to Figure 21 for mini-
mum dimensions and mounting detail.
Note: Hearth Extension must not cover the air inlet
opening of a fireplace.
The hearth extension described in Figure 21 must be
a durable non-combustible material with a minimum
(total) Rt value of 1.09; refer to Figure 22 for examples.
The overall height (above a combustible floor), depth
and width must be as indicated, with the extension cen-
tered to the fireplace opening.
The top of insulation must be covered with a non-com-
bustible decorative covering
or
a piece of .018” mini-
mum sheet metal, to protect hearth extension material.
(Fig. 21)
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 fireplace
hearth and hearth extension with a non-combustible
material. (Figs. 21 and 23)
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
56O
" minimum
May install
noncombustible
decorative
covering
OR
.018" min.
sheet metal
Fireplace
Hearth
Combustible
Floor
Minimum
Insulation
Value "R"
4" MIN.
FP594b
BFC combustible min.
8/21/00 djt
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" 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.
Shaded area
starts 1/2" from
away from edge
of unit 4"
FP594b
Fig. 21
Combustible side wall protection and hearth extension dimensions.
A
B
C
D
E
F
G
H
J
M400BFC
26”
12”
17°
25°
12”
8”
8”
18”
47
Z\v
”
660 mm 305 mm
305 mm 203 mm 203 mm 457 mm 1200 mm
