24
7�
Slip the flashing over the pipe section protruding through the roof. Secure the base of the flashing to the
roof with roofing nails. Use a non-hardening sealant between the uphill edge of the flashing and the roof.
Insure the roofing material overlaps the top edge of the flashing as shown in Figure 29. Verify that you
have at least the minimum clearance to combustibles at the roof line.
8� Continue to add pipe sections until the height of the vent cap meets the minimum code requirements.
Refer to Figure 30 and Table 5. Note that for steep roof pitches, the vent height must be increased. In
high wind conditions, nearby trees, adjoining roof lines, steep pitched roofs, and other similar factors can
result in poor draft, or down drafting. In these cases, increasing the vent height may solve the problem.
9�
Slip the storm collar over the pipe, and push it down to the top of the roof flashing as shown in Figure 29.
Use the non-hardening sealant around the joint between the pipe and the storm collar.
10� Twist-lock the vent cap.
Roof Pitch
Minimum Height
Feet
Meters
Flat to 7/12
1
0.3
Over 7/12 to 8/12
1.5
0.46
Over 8/12 to 9/12
2
0.61
Over 9/12 to 10/12
2.5
0.76
Over 10/12 to 11/12
3.25
0.99
Over 11/12 to 12/12
4
1.22
Over 12/12 to 14/12
5
1.52
Over 14/12 to 16/12
6
1.83
Over 16/12 to 18/12
7
2.13
Over 18/12 to 20/12
7.5
2.29
Over 20/12 to 21/12
8
2.44
Figure 30: Height of Vertical Termination; Reference
Table 5�
NOTES:
(a)
If an offset is necessary in the attic to avoid
obstructions, it is important to support the vent pipe
every 3 feet (91 cm), to avoid excessive stress on
the elbows, and possible separation. Wall straps are
available for this purpose (see Figure 31).
Initial Installation
QUALIFIED INSTALLERS ONLY
Table 5:
Minimum ‘H’ for Figure 30
(b)
When ever possible, use 45
°
degree elbows instead of 90
°
degree elbows. The 45
°
degree elbow offers
less restriction to the flow of flue gases and intake air.
(c)
For multi story installations. A ceiling firestop is required at the second floor, and any subsequent floors
(see Figure 32). The opening should be framed to 10” (25.4 cm) x 10” (25.4 cm) inside dimensions, in
the same manner as shown in Figure 28.
(d)
Any occupied areas above the first floor, including closets and storage spaces, which the vertical vent
passes through, must be enclosed. The enclosure may be framed and sheet rocked with standard
building materials. However consult the appliance manufactures installation instructions for the
minimum allowable clearance between the outside of the vent pipe, and the combustible surfaces of
the enclosure. Do not fill any required air spaces with insulation.
