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Step 6. Cut a hole in
the roof centered on
the
small
drill
hole
placed in the roof in
Step 2. The opening
should be of sufficient
size
to
meet
the
minimum requirements
for
clearance
to
combustibles,
as
specified.
Continue
to
assemble
pipe
sections and elbows as
necessary 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 higher
corrosion resistance.
Pipe
Extension
Pipe
Section
Figure 35
ST987
pipes
NOTES:
8/07
1. If exact lengths or distances must be met between elbow
offsets or elsewhere, use the pipe extensions to adjust
onto standard pipe sections. (Figure 35)
2. If an offset is necessary in the attic to avoid obstructions,
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 purpose. (Figure 36)
3. Wherever possible, use 45° elbows instead of 90°
elbows. The 45° elbow offers less restriction to the flow
of flue gases and intake air.
20
Ceiling
Joists
Cut
and
Frame
Decorative
Ceiling Support
Cover
1
⁄
" Wood
1
2
Screws
Figure 34
ST986
thru ceiling
8/07
Wall Strap
/ Plumbers
Tape
45°
Elbow
Figure 36
ST988
offset
8/07
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 the
top edge of the roof flashing. (Figure 38) Verify that you
have at least the minimum clearances to combustibles at
the roofline and in the attic.
Figure 37
Roor Pitch
Flat 7/12
Over 7/12 to 8/12
Over 8/12 to 9/12
Over 9/12 to 10/12
Over 10/12 to11/12
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
Step 8. Continue to add pipe sections until the height of
the system (before adding the cap) meets the minimum
45°
building codes requirements as described in Table 2, Figure
Elbow
37. Note that for steep roof pitches, the vent height must be
increased. In high wind conditions, nearby trees, adjoining
rooflines, steep pitched roofs and other similar factors
can result in 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. (Figure 38) Use non-
hardening sealant between the storm collar and the pipe
section
Dimension 'H'
from Table 2
H
Table 2
Minimum Height
ST989
chimney height
1' (914 mm)
8/07
1'6" (45 mm)
2' (61 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" (2.3m)
8' (2.4 m)
20012761
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