VENT INSTALLATION
3.Cut a hole in the roof using the locating hole as a center point. (Cover any exposed open vent pipes before cutting hole in roof). The 91/2"x91/2" (241mm x 241mm) hole must be measured on the horizontal. Actual length may be larger depending on the pitch of the roof. There must be a 1" minimum clearance from the vent pipe to combustible materials. (Insulation should be considered a combustible material).
4.Connect a section of pipe and extend up through the hole.
NOTE: If an offset is needed to avoid obstructions, you must support the vent pipe every three (3) feet. Use wall straps for this purpose. See Figure 28, page 23. Whenever possible, use 45° elbows instead of 90° elbows. The 45° elbow offers less restriction to the flow of the flue gases and intake air.
5.Place the flashing over the pipe section(s) extending through the roof. 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. There must be a 1" clearance from the vent pipe to combustible materials.
6.Continue to add pipe sections until the height of the vent cap meets the minimum building code requirements.
NOTE: You must increase vent height for steep roof pitches. Nearby trees, adjoining roof lines, steep pitched roofs, and other similar factors may cause poor draft or
NOTE: If the vent pipe passes through any occupied areas above the first floor, including storage spaces and closets, you must enclose pipe. You may frame and sheetrock the enclosure with standard construction material. Make sure to meet the minimum allowable clearances to combustibles. Do not fill any of the required clearance spaces with insulation.
CATHEDRAL CEILING INSTALLATION
1.Remove shingles or other roof covering as necessary to cut the rectangular hole for the support box. Mark the outline of the cathedral ceiling support box on the roof sheathing using the locating hole as a center point.
2.Cut the hole 1/8" larger than the support box outline. See Figure 32.
3.Lower the support box through the hole in the roof until the bottom of the box extends at least 2" below the ceiling. See Figure 32. Align the support box vertically and horizontally using a level. Temporarily tack the support box in place through the inside walls and into the roof sheeting.
4.Using tin snips, cut the support box from the top corners down to the roof line and fold the resulting flaps over the roof sheeting. See Figure 33. Apply a bead of
5.Complete the cathedral ceiling installation by following the same procedures outlines in steps 2 through 6 for Flat Ceiling Installation, page 24 and above.
ROOF PITCH | H (feet) |
|
|
Flat to 6/12 | 1.0 |
|
|
Over 6/12 to 7/12 | 1.25 |
|
|
Over 7/12 to 8/12 | 1.5 |
Over 8/12 to 9/12 | 2.0 |
|
|
Over 9/12 to 10/12 | 2.5 |
|
|
Over 10/12 to 11/12 | 3.25 |
Over 11/12 to 12/12 | 4.0 |
|
|
*H = Minimum height from roof to lowest
discharge opening of vent.
Figure 33 - Minimum chimney clearance
54D5031 | 25 |
