DuraVent DuraPlus HTC - Manual (Page 11)

11
Figure 12
at least a minimum of 10 inches (250 mm)
high, but must also extend above the level of
the insulation. The Firestop Radiation Shield
has a telescoping
extension to reach higher
if needed (maintain a minimum 1" overlap
between the two shield sections). If a taller
height is needed for the Cathedral Ceiling
Support Box, a field-fabricated extension of
the Box can be made of 26-gauge galvanized
(or heavier) material. Install the attic shield as
follows:
a. Assemble Chimney Sections until at least
15 inches (375 mm) of chimney extends
above the Firestop Radiation Shield or
Cathedral Ceiling Support Box.
b. Verify the height of the Firestop Radiation
Shield or Cathedral Ceiling Support Box is at
least 10 in (250 mm) above the attic framing
and is above the insulation level. Adjust the
Firestop Radiation Shield as needed, or add
an extension to the Support Box.
c. Secure the telescoping Firestop Radiation
Shield in place with at least (2) sheet metal
screws. Verify the telescoping shields overlap
at least 1".
d. Wrap the Attic Insulation Collar or Firestop
Radiation Shield Collar around the chimney
and fasten it loosely. Slide the Collar down
to meet the Firestop Radiation Shield or
Cathedral Ceiling Support Box. Slip the tab
through the adjacent slot and fold it back to
tighten and secure the Collar (Fig 10 & 11).
9. Install Roof Radiation Shield: The Roof
Radiation Shield is only required when
the chimney is enclosed in a chase within
the attic space. It is not required when the
chimney is unenclosed in the attic space.
Center the Roof Radiation Shield in the
opening cut in the roof. Line up the Shield so
the L-Brackets are horizontal, and the Shield
hangs vertically. For sloped roofs, adjust the
position of the L-Brackets so the Radiation
Shield covers the roof framing members.
Verify the height of the Radiation Shield will
Figure 11
Figure 10
PUSH COLLAR DOWN
ONTO SUPPORT
BOx OR FIRESTOP
RADIATION SHIELD
CENTER ROOF
RADIATION
SHIELD AROUND
CHIMNEY AND
SECURE TO ROOF
WITH SCREWS
ADjUST POSITION OF
L-BRACKETS SO SHIELD
COVERS FRAMING OF
SLOPED ROOFS. TRIM
SHIELD TO MATCH
FLASHING IF NEEDED.