DuraVent DuraChimney II - Manual (Page 8)

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tension is needed to prevent the damper plate
from rattling when closed. Mount the Lintel
Hook to the masonry with the screws provided.
4. Attach Chimney: Attach the first Chimney
Section onto the Anchor Plate by using the
sheet metal screws provided. Always maintain
at least a 2-inch clearance to combustibles.
The 2-inch clearance is an air space; do not
fill that clearance space with any materials. If
an offset is required, refer to the Elbow Offset
Installation Section below.
5. Frame Openings: From the ceiling, drop a
plumb bob to the center of the fireplace’s flue
outlet and mark this center point on the ceiling.
Refer to Table 1 for the framing dimensions.
Mark appropriate cutting lines around the
center point. Cut a square hole in the ceiling.
Frame a level, square opening centered over
the hole that you have cut. Frame openings at
each floor level above the Fireplace (Fig. 4).
These openings are to hold the Firestop and
Attic Insulation Shield. Locate each opening by
dropping a plumb bob to the four corners of the
opening below. Maintain the minimum 2-inch
clearance/air-space.
6. Cut Roof Opening: If penetrating through
the roof, determine and cut an opening in the
roof directly above the opening below. The
cut opening must be at least 4-inches larger
than the chimney’s outside diameter to provide
at least a 2-inch clearance all around the
chimney. The chimney must be centered within
this opening and maintain the minimum 2-inch
clearance to combustibles.
7. Install Firestop: A Firestop is required on
each floor penetration in multistory installations.
Building Codes require a Firestop at every
floor/ceiling level, including where the chimney
penetrates into the attic. Figure 4 shows a
typical 2-story installation with an attic. Note:
a Firestop is not installed where the chimney
penetrates through the roof. The Firestop is
FRAMING
Figure 5
Figure 6
Figure 7
SECURE BRACKET TO FRAME
SUPPORT UP TO
25 FEET OF CHIMNEY
MAINTAIN 2" CLEARANCE
EACH SUPPLEMENTARY INSTALL SUPP. SUPPORT
IF HEIGHT EXCEEDS 50’
OR IF REQUIRED BY THE
FIREPLACE MANUFACTURE
FROM CHIMNEY TO FRAMING