Heatilator • CI60 • 4013-031 Rev M • 10/06
12
E. Construct the Chase
A chase is a vertical boxlike structure built to enclose the
¿
re-
place and/or its vent system. Vertical chimneys that run on
the outside of a building must be installed inside a chase.
Construction of the chase may vary with the type of build-
ing. These instructions are not substitutes for the require-
ments of local building codes. Local building codes MUST
be checked.
Chases should be constructed in the manner of all outside
walls of the home to prevent cold air drafting problems. The
chase should not break the outside building envelope in any
manner. All outer walls need to be insulated.
Building codes require false ceiling and ceiling
¿
restops at
each
À
oor of the chase or every 10 ft (3.05 m) of clear space
to control spread of
¿
re.
Walls, ceiling, base plate and cantilever
À
oor at the
¿
rst level
of the chase should be insulated. See Figure 3.5. Vapor and
air in
¿
ltration barriers should be installed in the chase as per
regional codes for the rest of the home. Additionally, Hearth
& Home Technologies recommends that the inside surfac-
es be sheet rocked and taped (or the use of an equivalent
method) for maximum air tightness.
Ceiling
Firestop
Metal Chase Top
Round Termination Cap
False Ceiling
Insulation in the
outside walls
of the chase
Attic
Insulation
Shield
Chimney
Ceiling
Firestop
Tabs
False Ceiling
False Ceiling
Insulation
Insulation
Figure 3.5
Chase Assembly
F. Chimney Requirements
When planning your
¿
replace location, the chimney construc-
tion and necessary clearances must be considered. The
¿
re-
place system and chimney components have been tested to
provide
À
exibility in construction. The following
¿
gures are
the minimum distances from the base of the
¿
replace.
1
2
3
All outside walls should be insulated.
Figure 3.6
Chase Constructions
1. Fireplace and chimney enclosed in an exterior chase.
2. Chimney offset through exterior wall and enclosed in
chase.
3. Chase constructed on roof.
Gas line holes and other openings should be caulked with
high temperature caulk or stuffed with unfaced
¿
berglass in-
sulation. If the
¿
replace is being installed on a cement slab,
we recommend that in cold climates, a sheet of plywood or
other raised platform be placed underneath to prevent con-
ducting cold up into the room.
Three examples of chase applications are shown in Fig-
ure 3.6
Note:
A maximum of two pairs of offsets and returns may
be used.
ft
m
• Minimum overall straight height
18
5.5
• Minimum height with offset/return
18.5
5.6
• Maximum height
90
27.4
• Maximum chimney length between an offset and
return
20
6
• Maximum distance between chimney stabilizers
35
10.7
• Double offset/return minimum height
24
7.3
• Maximum unsupported chimney length between the
offset and return
6
1.8
• Maximum straight unsupported chimney height above
the
¿
replace
35
10.7
• Maximum unsupported chimney above roof
6
1.8
¨
