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10. With the flex vent assembly and the 48” long hard pipe
components laid out on the floor, begin securing these parts
together. First, apply a generous bead of silicone sealant to
the inside of the 4” diameter flex flue (not the end with the
pre-installaed connector), then slide the flex flue over the 4”
diameter hard pipe flue. Be sure to overlap at least 1-1/4”. Se-
cure this connection with a 4” diameter band clamp provided.
Be careful not to damage or tear the flex flue when tightening
clamp.
11. Repeat the connection process for the outer 7” diameter flex
vent to hard pipe connection. Use silicone sealant at this joint
also, overlap at least 1-1/4”, then secure the joint with the 7”
diameter band clamp provided. Be careful not to damage or
tear the flex vent pipe when tightening the clamp.
12. While the venting is still on the floor, assemble the roof jack
components as shown in Figure 29 and pre-install the roof
jack assembly to the hard pipe approximately 18” from the
top end of the hard pipe.
13. Now the pre-assembled vent system may be carried to the
roof, then lowered through the roof cutout opening (see step
5). Feed the flex vent end down through the roof opening and
firestop/thimble assembly installed in steps 4 through 6.
14. Secure the roof support assembly to the roof sheathing with
at least (4) nails/screws through each support bracket. Check
that the combustible clearances through the roof framing will
maintain at least a 1” clearance from the vent pipe.
15. Determine how high the vent terminal should be located
above the roof line based on the roof pitch information shown
in Figure 30. Adjust the vent system height by loosening the
pre-installed roof support pipe clamp and sliding the vent
pipe up or down as pre-determined, then re-tighten the pipe
clamp. Install a couple of sheet metal screws through the pipe
clamp into the outer hard vent pipe to lock in place.
16. Check to make sure that the bottom end of the flex vent is
long enough to reach the fireplace adapter collars. If too long,
trim off the extra flex vent not needed.
WING NUT (2)
PIPE CLAMP
ROOF BRACKET (2)
NUT (2)
SCREW (2)
H
X
12
ROOF PITCH IS X/12
H (Min.) - Minimum height from
roof to lowest discharge opening
DISCHARGE
LOWEST
OPENING
VENT CAP
GAS VENT
Figure 29
Figure 30
ROOF PITCH
H (Min.)
Flat to 6/12
12” (305mm)
6/12 to 7/12
15” (381mm)
Over 7/12 to 8/12
18” (457mm)
Over 8/12 to 16/12
24” (610mm)
Over 16/12 to 21/12
36” (914mm)