Construct The Chase - Heatilator CONSTITUTION C-40 Owner's Manual

E. Construct the Chase
A chase is a vertical boxlike structure built to enclose the fire-
place and/or its vent system. Vertical chimneys that run on
the outside of a building must be installed inside a chase.
In cold climates, it is recommended that the chase insulated
using batt type insulation between the joists.
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 firestops at
each floor of the chase or every 10 ft (3048 mm) of clear
space to control spread of fire.
Walls, ceiling, base plate and cantilever floor at the first level
of the chase should be insulated. See Figure 14.1. Vapor
and air infiltration 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
surfaces be sheet rocked and taped (or the use of an equiv-
alent method) for maximum air tightness.
Holes and other openings should be caulked with high tem-
perature caulk or stuffed with unfaced fiber glass insulation.
WARNING
Fire Risk
• DO NOT pack insulation or other
combustibles: between ceiling firestops;
between chimney and attic insulation
shield.
• ALWAYS maintain specified clearances around chimney
and ceiling firestop systems.
• Install ceiling firestops as specified.
Failure to keep insulation or other material away from
chimney pipe may cause fire.
Materials
a. The chase is constructed using framing materials
much the same as the walls in your home. A variety
of siding materials may be used including brick, stone,
veneer brick, or standard siding materials.
b. In constructing the chase, several factors must be
considered:
1) Maintain a 2 in. (51 mm) air space around the
chimney.
2) The chase top must be constructed of non-com-
bustible material.
3) In cold climates, a firestop spacer should be
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Heatilator • Constitution EPA Fireplace • 480-1091C
installed in an insulated false ceiling at the 8 ft.
(2438 mm) level above the fireplace assembly.
This reduces heat loss through the chase.
4) In cold climates, the walls of the chase should
be insulated to the level of the false ceiling as
shown in Figure 14.1. This will help reduce heat
loss from the home around the fireplace.
Round Termination Cap
Storm Collar
Metal Chase Top
Ceiling
Firestop
False Ceiling
Attic
Insulation
Tabs
Shield
Ceiling
Firestop
Insulation
Insulation
False Ceiling
False Ceiling
Chimney
Figure 14.1 Chase Assembly
Three examples of chase applications are shown in Fig-
ure 14.2.
1. Fireplace and chimney enclosed in an exterior chase.
2. Chimney offset through exterior wall and enclosed in
chase.
3. Chase constructed on roof.
All outside walls should be insulated.
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Figure 14.2 Chase Constructions
Insulation in the
outside walls
of the chase
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November 11, 2008
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