Initial Installation
QUALIFIED INSTALLERS ONLY
STEP 5. Cut hole in the roof centered on the small hole placed in the roof from Step 2. The hole should be of sufficient size to meet minimum requirements for Clearance to Combustibles, as specified. Continue to assemble lengths of pipe and elbows necessary to reach from the ceiling support box up through the roof line. Galvanized pipe and elbows may be utilized in the attic, as well as above the roof line. The galvanized finish is desirable above the roof line, due to the higher corrosion resistance.
STEP 6. Once the pipe sections have been joined, and run up through the hole in the roof, slip an elbow strap over the exposed sections, bend the support straps outwards, and push the elbow strap down to the roof level, as shown in Figure 23. Tighten the clamp around the pipe section. Use a level to make sure the pipe is truly vertical. With roofing nails, secure the support straps to the roof. Seal the nails holes heads with
STEP 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
STEP 8. Continue to add pipe sections until the height of the vent cap meets the minimum code requirements. Refer to Figure 24 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 23. Use the
STEP 10. Twist-lock the vent cap.
Figure 24: Height of Vertical Termination;
Reference Table 3.
Table 3: Minimum ‘H’ for Figure 24
Roof Pitch | Minimum Height (H) | |
|
|
|
| Feet | 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 |
|
|
|
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