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5. Place the flashing over the pipe section(s) extending
through the roof. Apply a bead of silicone or roof sealer to the
bottom flange of the flashing and secure the base of the
flashing to the roof and framing with roofing nails. Be sure
roofing material overlaps the top edge of the flashing as
shown in figure 28. There must be a 1" clearance from the
vent pipe to combustible material.
6. Continue to add pipe section(s) until the height of the vent
cap meets the minimum building code requirements described
in figure 15. Note you must increase the vent height for steep
roof pitches, nearby trees, adjoining rooflines and other
adjacent factors, which may cause poor drafting or a down-
draft condition (see figure 29). Increasing the vent height may
solve this problem.
7. Apply a bead of sealer to the upper edge of the flashing
collar and slide the storm collar over the pipe and down on the
top edge of the flashing. Apply a second bead of silicone or
roof sealer around the remaining seam of the storm collar.
Twist-lock the vent cap onto the last section of vent pipe and
seal with high temperature silicone as specified in the warning
statement on page 7. Finish sealing the flange around the
roofing material with roofing sealer.
Note: If the vent pipe passes through any occupied areas
above the first floor, including storage spaces and closets, you
must enclose the entire exposed pipe. You may frame and
sheetrock the enclosure with standard construction materials.
Make sure the enclosure meets the minimum allowable
clearances to combustibles. Do not fill any of the required air
spaces with insulation.
VERTICAL TERMINATION CONFIGURATIONS
Figures 31 through 34 show four different configurations for
vertical termination. These minimum vertical rises are based
on horizontal runs with a minimum of 1/4" upwards pitch per
foot and do not reflect constraints on a vertical system with
45° or greater offsets.
Any offset pitch of 45° or less must be considered horizontal
and sized within the maximum allowable lengths listed in the
following examples. All connections must be sealed with high
temperature silicone sealant as specified in the warning
statement on pg. 7.
45° STARTER
ELBOW
REQUIRED
Figure 31
VERTICAL RIGID VENTING
CONFIGURATION USING TWO 90 DEG. ELBOWS
WITH TWO HORIZONTAL RUNS
VERTICAL (V)
HORIZONTAL (H1) + (H2)
5' min.
2' max.
6' min.
4' max.
7' min.
6' max.
8' min.
8' max.
20' max.
8' max.
VENTING WITH TWO 90 DEG. ELBOWS
ELBOW
REQUIRED
45° STARTER
Figure 32
VERTICAL RIGID VENTING
CONFIGURATION USING ONE 90 DEG. ELBOW
VERTICAL (V)
HORIZONTAL (H)
5' min.
2' max.
6' min.
4' max.
7' min.
6' max.
8' min.
8' max.
20' max.
8' max.
VENTING WITH ONE 90 DEG. ELBOW