Lennox Montebello DLX Installation Instructions Manual page 15

LENNOX HEARTH PRODUCTS • MONTEBELLO
One method of support is by utilizing field
provided support straps (conventional
plumber's tape). Secure the plumber's tape
to the framing members with nails or screws.
Strap the tape around the vent, securing the
ends of the tape to the framing. If desired,
sheet metal screws #6 x 1/2 in. length may
be used to secure the support straps to the
vent pipe. See Figure 18 on Page 14.
F. Change vent direction to horizontal/
inclined run—At transition from or to a
horizontal/inclined run, install the SV8 E45
and SV8 E90 elbows in the same manner as
the straight vent sections. The elbows feature
a twist section to allow them to be routed
about the center axis of their initial collar
section to align with the required direction
of the next vent run element. Twist elbow
sections in a clockwise direction only so as
to avoid the possibility of unlocking any of
the previously connected vent sections. See
Figure 17 on Page 14 and Figure 19.
6"
(153mm)
Swivel Joint Swivel Joint
(360° swivel) (360° swivel)
SV8E45 SV8E90
(45° Elbow) (90° Elbow)
Figure 19
G. Continue installation of horizontal/
inclined sections—Continue with the
installation of the straight vent sections in
horizontal/inclined run as described in Step
C. Install support straps every 3 ft (914 mm)
along horizontal/inclined vent runs using
conventional plumber's tape. See Page 17,
Figure 26. It is very important that the
horizontal/inclined run be maintained in a
straight (no dips), slightly elevated plane. The
recommended incline is approximately 1/4 in.
per foot (20 mm per meter) horizontal, in
a direction away from the fireplace. The
rise per foot run ratios that are smaller are
acceptable all the way down to at or near
level. Use a carpenter's level to measure from
a constant surface and adjust the support
straps as necessary.
It is important to maintain the required
clearances to combustibles: 1 in. (25 mm)
at all sides for all vertical runs; and 3 in.
(76 mm) at the top, 1 in. (25 mm) at sides,
and 1 in. (25 mm) at the bottom for all
horizontal/inclined runs.
H. Frame roof opening—Identify location for
vent at the roof. Cut and/or frame opening
per Roof Framing Chart (Figure 20).
DLX DIRECT VENT GAS FIREPLACES (MDLX40/45) • INSTALLATION INSTRUCTIONS
®
Framing Dimensions for Roof
Inches (millimeters)
Pitch
0/12
6/12
12/12
Figure 20: Roof Framing
I. Install the roof flashing—Extend the vent
sections through the roof structure. Install
the roof flashing over the vent section and
10"
position such that the vent column rises
(254mm)
vertically (use carpenters level) (Figure
21). Nail along perimeter to secure flashing
or adjust roofing to overlap the flashing
edges at top and sides only and trim where
necessary. Seal the top and both sides of the
flashing with waterproof caulking.
J. Install the storm collar—Install the storm
collar, supplied with the flashing, over the
vent/flashing joint (see Figure 21). Loosen
the storm collar screw. Slide collar down
until it meets the top of the flashing. Tighten
the adjusting screw. Apply non-combustible
caulking or mastic around the circumference
of the joint to provide a water tight seal.
Flashing
Figure 21
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
C
D
C D
13 in. 13 in.
(330 mm) (330 mm)
13 in. 15-1/2 in.
(330 mm) (394 mm)
13 in. 20-1/2 in.
(330 mm) (541 mm)
Storm
Storm
Collar
Collar
K. Install the vertical termination—The
final step involves installation of the Vertical
Termination. Extend the vent sections to
the height as shown in the "Vertical vent
termination section" on Page 6. The SV8VTR
Vertical Termination (Figure 22) can be
installed in the exact same fashion as any
other Secure Vent section. Align the
®
termination over the end of the previously
installed section, adjusting the radial
alignment until the four locking dimples of
the termination are aligned with the inlets
of the four incline channels of the last vent
section. Push the termination down until
it fully engages, then twist the termination
clockwise running the dimples down and
along the incline channels until they seat at
the end of the channels.
Figure 22
If the vent system extends more than 5 feet
(1.5 m) above the roof flashing, stabilizers
may be necessary. Additional screws may
be used at section joints for added stability.
Guide wires may be attached to the joint
for additional support on multiple joint
configurations.
15