DuraVent DuraChimney II - Manual (Page 7)

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according to the fireplace manufacturer’s
installation instructions. The flue outlet should
be placed between the rafters or joists above,
if possible.
2. Determine Chimney Size: Follow the
fireplace manufacturer’s instructions for
chimney size or use Table 2 (pg 11) to
determine the correct diameter chimney for
your fireplace.
3. Mount Anchor Plate: Chimneys for
masonry fireplaces begin with an Anchor
Plate or Anchor Plate with Damper. Warning:
Anchor Plate with Damper is not allowed in
chimneys serving stoker-fired, liquid or gas-
burning appliances. Caution: Do not install
Anchor Plate with Damper on Factory-built
fireplaces. Important: be sure the surface
of the masonry chimney has a level surface
on which to attach the Anchor Plate or
Anchor Plate. If the top of the masonry does
not have a level surface, then you will need to
modify the masonry accordingly. Center the
Anchor Plate over the masonry flue opening.
If a Damper is used, make sure nothing
interferes with the damper plate movement.
Seal the Anchor Plate in place with a high-
temperature sealant. Secure Anchor Plate
with (4) 2” x 1/4” masonry anchors (Fig. 2).
3a. Damper Plate: The Damper Plate should
swing freely once the Anchor Plate is installed.
When the chain is pulled down, the damper
plate should close (horizontal position). When
the chain is released (no weight on the chain),
the damper should swing open (vertical
position).
3b. Lintel Hook: With the damper plate in
the closed (horizontal) position, determine
and mark the location for the Lintel Hook. The
Lintel Hook should be mounted in a position
so as to provide a small amount of tension in
the spring attached to the chain (Fig. 3). The
Figure 4
FIREPLACE
OR ANCHOR PLATE
FIRESTOP
SQUARE FRAME
CHIMNEY
FIRESTOP
ATTIC INSULATION
CHIMNEY SECTION
CHASE TOP
STORM
TERMINATION
SHIELD & COLLAR
CAP
COLLAR
SQUARE FRAME
FLASHING
(4) ROOF
RADIATION
SHIELDS
ANCHOR PLATE
WITH DAMPER