Initial Installation
QUALIFIED INSTALLERS ONLY
STEP 8. Continue to add pipe sections until the height of the vent cap meets the minimum code requirements. Refer to Figure 16 and Table 3. 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.
STEP 9. Slip the storm collar over the pipe, and push it down to the top of the roof flashing as shown in Figure 15. Use the
STEP 10.
NOTES:
(1)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 17).
(2)When ever possible, use 45° degree elbows instead of 90°
Figure 17: Use of Wall Straps.degree elbows. The 45° degree elbow offers less restriction to
the flow of flue gases and intake air.
NOTES:
(1)For multi story installations. A ceiling firestop is required at the second floor, and any subsequent floors (see Figure 14). 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 14.
(2)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 sheetrocked 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.
Figure 18: Multi-Story Vent Pipe Installation.
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