16
16
Top Vent Connection—Through the Roof
Termination*
See
fi
gure 16.
Adapter #817VAK, pipe lengths, a vertical vent terminal
and roof
fl
ashing will be required. Various other ceiling or
roof items may be necessary depending on the particular
installation. See venting accessories list on pages 39–40 for
allowable components.
Top Vent Connection—Offset and Through the
Roof Termination*
See
fi
gure 17.
For situations where offset is necessary in an attic to avoid
obstructions or allow useful space.
Adapter #817VAK, two 45° vent elbows, wall straps, pipe
lengths, a vertical vent terminal and roof
fl
ashing will
be required. Various other ceiling or roof items may be
necessary depending on the particular installation. See
venting accessories list on pages 39–40 for allowable
components.
*Note
The distance from the roof to the lowest terminal
discharge opening depends on the roof pitch and must
be in accordance with the manufacturer’s instructions
supplied with the termination unit.
The venting system for these appliances is considered
to be a
Special Venting System
.
The rule in the
Natural
Gas and Propane Installation Code CAN/CGA-B149
requiring a minimum vent height of 2’ above any portion
of a building within 10’ does not, therefore, apply. See
fi
gure 17a.
1.
2.
‘H’
Horizontal
overhang
Vertical
wall
Termination
cap
Storm
collar
Roof
flashing
Plumber’s tape
fixed to wall strap
Wall strap
Ceiling
firestop
Ceiling
support
Offset elbows
Min.
18”
Overhang should
not extend beyond
vent if within 48” of
termination cap
Min. 24”
(unvented soffit)
Min. 36”
(vented soffit)
Roof Pitch
Minimum
‘H’ (feet)
Flat to 7/12
1’
Over 7/12 to 8/12
1.5’
Over 8/12 to 9/12
2’
Over 9/12 to 10/12
2.5’
Over 10/12 to 11/12
3.25’
Over 11/12 to 12/12
4’
Over 12/12 to 14/12
5’
Figure 17a
40’ (12.2 m) max.
10’ (3.05 m) min.
5-9/16” (142 mm)
min.
from hole
center
to back
wall
2” (51 mm) min.
clearance to
combustible
materials
all round
16”
(41 cm)
min.
Figure 16
Figure 17
4’6” (1.37 m)
max.
40’ (12.2 m) max.
12’ (3.66 m) min.
2” (51 mm) min.
clearance to
combustible
materials
all round
16”
(41 cm)
min.
Location
