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VERTICAL TERMINATION
Locate and mark the center point of the vent pipe using a nail on
the underside of the roof. Drive the nail through the center point.
Mark the outline of the roof hole around this center point.
NOTICE:
Size of the roof hole dimensions depend on the pitch
of the roof. Maintain a 2 inch (50 millimeter) clearance
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. Non-hardening sealant should be used to completely seal this
flashing installation.
Determining Minimum Vent Height Above the Roof.
WARNING
Major U.S. building codes specify minimum chimney and/
or vent height above the roof top. These minimum heights
are necessary to prevent a fire. These specifications are
summarized in Figure 64
.
ROOF PITCH
MINIMUM HEIGHT
(Inches)
(Millimeters)
Flat to 6/12
12
305
6/12 to 7/12
15
381
Over 7/12 to 8/12
18
457
Over 8/12 to 16/12
24
610
Over 16/12 to 21/12
36
914
Figure 64
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
this problem.
General Maintenance
Inspect venting system semi-annually as follows:
1. Check for corrosion areas of the venting system exposed to
the elements. These will appear as rust spots or streaks and,
in extreme cases, holes. Replace damaged components should
immediately.
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 termination shall not be recessed into a wall or siding.
A removable panel or other means must be provided in the enclosure
for visual inspection of the flue connection.
NOTICE:
This also pertains to vertical vent systems installed on
the outside of the building.
Slide the vertical vent cap over the ends of the vent pipe and secure.
See Figure 65.
Installing the Vent System in a Chase
A chase is a vertical structure built to enclose the gas fireplace and/
or its vent system. Vertical vent runs on the outside of a building
may be, but are not required to be installed inside a chase.
Figure 65
CAUTION
Installation requirements for firestop spacers and construction
of the chase may vary with the type of building. Check local
building codes to determine the requirements.
NOTICE:
Build the chase large enough to the minimum clearance
of combustible materials (including insulation) to the vent system.
When installing the vent system in a chase, insulate the chase as you
would the outside walls of your home. This is especially important
in cold climates. Upon completion of chase framing, install the vent
system by following the instructions in this manual.
