Filter
Top Products
support straps to the roof. Seal the nails holes heads with non-hardening mastic. Trim the excess
length of the support straps that extend out beyond the edge of the ashing.
7. Slip the ashing over the pipe section protruding through the roof. Secure the base of the ashing to
the roof with roong nails. Use a non-hardening sealant between the uphill edge of the ashing and
the roof. Insure the roong material overlaps the top edge of the ashing as shown in Figure 30. 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 31 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 ashing as shown in Figure
H
Dimension ‘H’ obtained
from table below.
Table 5: Minimum ‘H’ for Figure 31.
Roof Pitch Minimum Height
Ft Meters
Flat to 7/8 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 31: Height of Vertical Termination;
Reference Table 5.
23
Initial Installation
QUALIFIED INSTALLERS ONLY
plumber’s tape
connected to
wall strap
Wall strap
45° elbows (x2)
Figure 32: Use of Wall Straps.
30. Use the non-hardening sealant around the
joint between the pipe and the storm collar.
10. Twist-lock the vent cap.
NOTES:
• If an offset is necessary in the attic to avoid obstructions,
it is important to support the vent pipe every 3 ft (91
cm), to avoid excessive stress on the elbows, and possible
separation. Wall straps are available for this purpose (see
Figure 32).
• When ever possible, use 45° degree elbows instead of
90° degree elbows. The 45° degree elbow offers less
restriction to the ow of ue gases and intake air.