Construct The Chase - Heatilator BIR50-B Installation Manual

C. Construct the Chase
A chase is a vertical boxlike structure built to enclose the
fi replace and/or its vent system. Vertical chimneys that
run on the outside of a building must be installed inside a
chase.
In cold climates, Hearth & Home Technologies recom-
mends that the chase be well 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 fi restops/
attic shields at each fl oor of the chase or every 10 ft (3048
mm) of clear space to control spread of fi re.
Walls, ceiling, base plate and cantilever fl oor at the fi rst
level of the chase should be insulated (see Figure 3.3.)
Vapor and air infi ltration barriers should be installed in the
chase as per regional codes for the rest of the home. Ad-
ditionally, Hearth & Home Technologies recommends that
the inside surfaces be drywalled and taped (or the use of
an equivalent method) for maximum air tightness.
Holes and other openings should be caulked with high
temperature caulk or stuffed with unfaced fi ber glass
insulation.
WARNING! You must install false ceilings and ceil-
ing fi restops at each fl oor of the chase or every 10 ft
(3.05 m) to control spread of fi re.
WARNING! Risk of Fire! DO NOT seal area between fi re
stop opening and chimney pipe except where they enter
the attic or leave the warm air envelope of the home (use
600° F sealant).
• 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.
• In constructing the chase, several factors must be
considered:
- Maintain a 2 in. (51 mm) air space around the
chimney.
- The chase top must be constructed of non-
combustible material.
- In cold climates, a fi restop spacer and attic insulation
shield should be installed in an insulated false ceiling
at the 8 ft. (2438 mm) level above the fi replace
assembly. This reduces heat loss through the chase.
- In cold climates, the walls of the chase should be
insulated to the level of the false ceiling as shown in
Figure 3.3. This will help reduce heat loss from the
home around the fi replace.
Heatilator • Birmingham BIR50-B Installation Manual • 4059-701 • Rev B • 2/6/13
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 3.3 Chase Assembly
WARNING! Risk of Fire!
2 in. (51 mm) air space clearance to insulation and other
materials surrounding the chimney system.
• Insulation and other materials must be fi rmly secured to
prevent accidental contact with chimney system.
• The chase must be properly blocked to prevent blown
insulation or other combustibles from entering and
making contact with fi replace or chimney.
• Failure to prevent contact between insulation or other
materials and chimney system may cause overheating
and fi re.
Three examples of chase applications are shown in Fig-
ure 3.4.
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.
1
Figure 3.4 Chase Constructions
Insulation in the
outside walls
of the chase
You must maintain a minimum
2 3
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