Vermont Castings Intrepid INDVRCB Homeowner's Installation And Operating Manual page 20

Intrepid® Direct Vent - Rear Vent Gas Heater
Figure 34
Ceiling
Joists
Cut
and
Frame
Decorative
Ceiling Support
Cover
1¹⁄₂" Wood
Screws
NOTES:
1. If exact lengths or dis-
tances must be met be-
tween elbow offsets or
elsewhere, use the pipe
extensions to adjust onto
standard pipe sections.
(Fig. 35)
2. If an offset is necessary
in the attic to avoid ob-
structions, it is important
to support the vent pipe in
order to avoid excessive
stress on the elbows. Wall
straps or plumber tape
may be used for this pur-
pose. (Fig. 36)
3. Wherever possible, use 45° elbows instead of 90° el-
bows. The 45° elbow offers less restriction to the flow
of flue gases and intake air.
Step 7. Slip the roof flashing over the pipe section(s) pro-
truding through the roof. Use a non-hardening sealant be-
tween the roof flashing and the roofing to prevent water
leakage. Secure the base of the roof flashing to the roof
with roofing nails. Ensure the roofing material overlaps
20
semble pipe sections
and elbows as neces-
sary to reach up through
the roof line. Galvanized
pipe and elbows may
be utilized in the attic,
as well as above the
roofline. The galvanized
finish is desirable above
the roofline, due to high-
er corrosion resistance.
Figure 35
Pipe
Section
ST986
ST987
Figure 36
Wall Strap
/ Plumbers
Tape
45°
Elbow
ST988
the top edge of the roof flashing. (Fig. 38) Verify that you
have at least the minimum clearances to combustibles at
the roofline and in the attic.
Step 8. Continue to add pipe sections until the height of
the system (before adding the cap) meets the minimum
building codes require-
ments as described
in Table 2, Figure 37.
Note that for steep
roof pitches, the vent
height must be in-
creased. In high wind
conditions,
Pipe
Extension trees, adjoining roofli-
nes, steep
roofs and other similar
factors can result in
Roof Pitch
Flat 7/12
Over 7/12 to 8/12
Over 8/12 to 9/12
Over 912 to 10/12
Over 10/12 to 11/12
Over 11/12 to 12/12
Over 12/12 to 14/12
Over 14/12 to 16/12
Over 16/12 to 18/12
Over 18/12 to 20/12
Over 20/12 to 21/12
poor draft, or down drafting. In these cases, increasing
the vent height or switching to the high wind termination
cap may help to solve the problem.
Step 9. Slip the storm collar over the pipe section, and
push it down to the top of the roof flashing. (Fig. 38) Use
non-hardening sealant between the storm collar and the
45°
pipe section
Elbow
Step 10. Holding the bottom of the termination cap only,
twist lock the cap onto the last pipe section protruding
above the roofline.
NOTES:
1. For multi-story vertical installations, a ceiling firestop
is required at the second floor, and any subsequent
floors. (Fig. 39) Cut and frame a 9" x 9" (229 x 229 mm)
square opening for installation of the ceiling firestop.
2. If vent passes through any occupied areas above the
first floor, including closets and storage spaces, it must
be enclosed. The enclosure may be framed and cov-
ered with sheet rock with standard construction materi-
als, but required clearances to combustibles must be
maintained. Consult these installation instructions for
the minimum allowable clearances between the out-
Figure 37
H
nearby
pitched
ST989
Table 2
Minimum Height
1' ST989 (914 mm)
chimney height
1'6" (457 mm)
8/07
2' (610 mm)
2'6" (762 mm)
3'3" (990 mm)
4' (1.2 m)
5' (1.5 m)
6' (1.8 m)
7' (2.1 m)
7'3" (2.3 m)
8' (2.4 m)
Dimension 'H'
from Table 2
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