VERTICAL TERMINATION
Locate and mark the center point of the venting pipe. Using a nail on the underside of the roof and drive this nail through this center point. Make the outline of the roof hole around this center point.
NOTE: Size of the roof hole dimensions depend on the pitch of the roof. There must be a 1 inch clearance (25mm) to the vertical pipe sections. This clearance is to all combustible material.
Cover the opening of the vent pipe and cut and frame the roof hole. Use framing lumber the same size as the roof rafters and install the frame securely. Flashing anchored to frame must withstand high winds. The storm collar is placed over this joint to make a water- tight seal.
Determining Minimum Vent Height Above the Roof.
WARNING: Major U.S. building codes specify minimum chimney and/orvent height above the roof top.These minimum heights are necessary in the interest of safety. These specifica- tions are summarized in Figure 43.
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VENT CAP |
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GAS VENT
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| ROOF PITCH IS X/12 | |||
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| ROOF PITCH | H (Min.) |
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| Flat to 6/12 | 12" (305 mm) |
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| 6/12 to 7/12 | 15" (381 mm) |
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| Over 7/12 to 8/12 | 18" (457 mm) |
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| Over 8/12 to 16/12 | 24" (610 mm) |
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Figure 43 | Over 16/12 to 21/12 | 36" (914 mm) |
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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
General Maintenance
Conduct an inspection of the venting system
1.Check areas of the venting system which are exposed to the elements for corrosion. These will appear as rust spots or streaks and, in extreme cases, holes. These components should immediately be replaced.
2.Remove the cap and shine a flashlight down the vent. Remove any bird nests or other foreign material.
3.Check for evidence of excessive condensate, such as water droplets forming in the inner liner and subsequently dripping out at joints. Condensate can cause corrosion of caps, pipe and fittings. It may be caused by having excessive lateral runs, too many elbows and exterior portions of the system being exposed to cold weather.
4.Inspect joints to verify that no pipe sections or fittings have been disturbed and, consequently, loosened.Also, check mechanical supports, such as wall straps or plumbers’ tape for rigidity.
Venting terminal shall not be recessed into a wall or siding.
Aremovable panel or other means must be provided in the enclosure for visual inspection of the flue connection.
NOTE: This also pertains to vertical vent systems installed on the outside of the building.
Slide the vertical top
Installing the Vent System in a Chase
A chase is a vertical
Figure 44
CAUTION: Treatment of firestop spacers and construction of the chase may vary with the type of building.These instructions are not substitutes for the requirements of local building codes. Therefore, your local building codes must be checked to determine the requirements for these steps.
NOTE: When installing this vent system in a chase, it is always good building practice to insulate the chase as you would the outside walls of your home. This is especially important for cold climate installations. Upon completion of building your chase framing, install the vent system by following the instructions in this manual. Remember to build the chase large enough so that minimum clearance of combustible materials (including insulation) to the vent system are maintained.
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