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3-90-30007474
Vermont Castings • Intrepid DV-IFT Owner’s Manual_R20 • 11/21
Step 5
- Using tin snips, cut the support box from the top
corners down to the roofline, and fold the resulting flaps
over the roof sheathing. The flaps may be trimmed as
needed, Figure 3.40. Before nailing it to the roof, run a bead
of non-hardening sealant around the support box to make
a seal between the support box and the roof. Clean out any
combustible material from inside the support box.
Step 6
- Follow Steps 4 and 5 of the Vertical Installation
instructions.
Step 7
- Place the support clamp (provided with the support
box) inside the support box (at the bottom), and secure
to the pipe section. The clamp allows the support box to
support the weight of the pipe sections. Continue to add
pipe sections until you are above the roofline.
Consult these
installation instructions
for the minimum
allowable clearances
between the outside of
the vent pipe and the
combustible surfaces
of the enclosure. Do
not fill required air
spaces with insulation.
3. If venting system
passes through an
attic space an attic
insulation shield
must be installed
to prevent contact
between pipe
sections and the
insulation. Nail the
base to floor of attic
and adjust shield
for appropriate
insulation level,
then attach the
collar at the top of
assembly, Figure
3.38. For vaulted
ceilings, the attic
insulation shield cannot be installed. To prevent building
insulation and other debris from entering the support
box or contacting the pipe, a chase enclosure can be
constructed around the support box. Ensure proper
clearance to combustibles are maintained.
ST990
above roof
8/07
High Wind Vertical
Termination
Roof Flashing
Storm Collar
Optional Low Profile
Termination Cap
Secure Flashing with
Non-hardening Sealant
and Roofing Nails
Figure 3.37
Figure 3.38
ST991
attic insul shield
8/07
Nails
Attic Insulation Shield
Required Clearance
Minimum Clearance
Minimum Clearance
Minimum Clearance
Figure 3.39
ST992
clg support box
8/07
Level
2” Min. Below
Finished Ceiling
Cut Hole 1/8” Larger
than Support Box
Cathedral Ceiling
Support Box
Cathedral Ceiling Installation
Step 1
- Follow installation Step 1 and 2 under Vertical
Termination.
Step 2
- Using the plumb bob, mark the centerline of the
venting system on the ceiling and drill a small hole through
the ceiling and roof at this point. From the roof, locate the drill
hole and mark the outline of the Cathedral Ceiling Support
Box.
Step 3
- Remove shingles or other roof covering as necessary
to cut the rectangular hole for the support box. Cut the hole
1/8” (3 mm) larger than the support box outline.
Step 4
- Lower the support box through the hole in the roof
until each side of the bottom of the support box protrudes
at least 2” (51 mm) below the ceiling, Figure 3.39. Align
the support box both vertically and horizontally with a level.
Temporarily tack the support box in place through the inside
walls and into the roof sheathing.
