6
Merrimack Large Insert
30004671
A,I
B
C
D,J
E
D,J
H
C E
FP1084
winterwarm
fireplace minimum dimensions
3/01
Fireplace Minimums
A. Width at Face
9
C\v
” (756 mm)
B. Width at Dimension ‘C’
5” (635 mm)
C. Depth
1
18
¹\₂
” (470 mm)
D. Height at Face
3
C\v
” (603 mm)
E. Height at Dimension ‘C’
3
C\v
” (603 mm)
Fireplace Maximums
H. Lintel depth
9”
(9 mm)
I. Width
45” (1143 mm)
J. Height
3” (813 mm)
FP1084
1. The minimum depth must be maintained from the floor of the fireplace
to a height of 1
¹\₂
” (540 mm)
. Though the Merrimack Large Insert will fit into larger fireplaces, the
decorative optional MHSC Surround Panels will not completely cover the
fireplace opening if these dimensions are exceeded. Custom made trim
pieces may be used.
Fig. 3
Use these measurements to confirm that the Merrimack
Large Insert will fit into your masonry fireplace.
clearance Requirements
After confirming that your fireplace is the right size,
check the clearance to combustibles. First mark with
tape the exact center of your fireplace opening on the
hearth. Measure the side clearance from this point.
Measure the top trim and/or mantel clearances from the
finished hearth surface. Measure the front clearance (to
furnishings, etc.) from the fireplace face. (Fig. 4)
X
FP1085
WinterWarm
clearances
3/01
C
A
B
Measure
side trim
clearance
from here
FP1085
Fireplace clearances
A. Mantel*
43” (109 mm)
B. Top Trim (1
¹\₂
”)
41” (1041 mm)
C. Side Trim**
C\v
” (578 mm)
* Clearance shown is for 1” (305 mm) deep mantel. Dimension
may be reduced to 41” (1041 mm) if the mantel is 8” (03 mm)
deep or less.
** Where side trim extends more than 1
¹\₂
” (38 mm) from the fire-
place facing, the side clearance must be no less than 31
¹\v
” (794
mm); this is also the required side wall clearance.
Measure the side clearance (C) from the exact center of your fire-
place opening on the hearth (X). Measure the top trim (B) and/or
mantel clearances (A) from the finished hearth surface. Measure
the front clearance (to furnishings, etc.) from the fireplace face.
Fig. 4
Observe these clearances to combustible trim.
hearth Requirements
In some fireplaces, the hearth in front of the fireplace
opening is brick, stone, slate, or some other non-com-
bustible material that is in direct contact with concrete
poured over earth. These are the only hearths that are
considered noncombustible. In other fireplaces, the
brick or concrete hearth in front of the fireplace opening
is supported by heavy wooden framing. Because nei-
ther brick nor concrete has good insulating properties,
heat radiated by the fire will pass downward through
the hearth to the wooden framing. Such hearths are
considered combustible.
The hearth for the Merrimack insert must be construct-
ed over a completely non-combustible surface (such as
unpainted concrete over earth). This non-combustible
hearth must extend at least 16” (406 mm) in front of the
doors as protection from heat radiated from the insert.
This means the non-combustible hearth must extend
3” in front of the fireplace face opening in a typical
installation.
In addition, spark and ember protection is needed 8”
(03 mm) to each side of the insert and in Canada,
18” in front of the insert. The approved construction of
this protection is a minimum or 4 gauge galvanized
sheet metal or equivalent. Figure 5 shows the details of
hearth requirements.
