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Locate and mark the center point of the vent pipe on the
underside of the roof. Drive a 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. There must be a 1 inch (25 mm) minimum
clearance to the vertical pipe sections. Maintain this
clearance to all combustible material.
To keep out debris, cover the opening of the vent pipe before you
cut and frame the roof opening. Use lumber the same size as the
roof rafters to frame the opening. Securely attach the flashing
to frame to withstand high winds. Place the storm collar over
this joint to make a water-tight seal. Seal the flashing with non-
hardening sealant.
Determining Minimum Vent Height Above the Roof.
Major U.S. building codes specify minimum chimney and
vent height above the roof top. These minimum heights
ensure safe operation of the fireplace. These specifications
are summarized in Figure 49.
VENT CAP
GAS VENT
NotICE: 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.
Installing the Vent System in a Chase
A chase is a vertical box-like 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.
Page 36
VERTICAL TERMINATION
WARNING
24"
24"
MORE
THAN
10 FEET
Figure 49
Treatment of firestop spacers and construction of the chase
may vary with the type of building. Check local building codes
to determine the requirements for these steps.
NotICE: Build the chase large enough to maintain 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.
The vertical termination cap for this fireplace must not be any
closer than 24 inches to combustible materials. See Figure 50.
24" MINIMUM
CLEARANCE TO
COMBUSTIBLES
NATURAL OR
MAN MADE
8' (2.44M)
MAX
40'
(12.19M)
8' (2.44M)
MAX
MAX
If two vertical terminations are run near each other, they may be
placed a minimum of 12 inches between them if they are at the
same height. See Figure 51. If two vent terminations are not at
the same height, they must be positioned at least 24 inches apart
to minimize draft issues between them.
CAUTION
45°
45°
Figure 50
12"
MINIMUM
Figure 51
37754-6-1019
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