Cathedral Ceiling Installation - DuraVent DirectVent Pro Installation Instructions Manual

CATHEDRAL CEILING
INSTALLATION
Step 1. Follow installation Steps 1 and
2 under Vertical Terminations.
Step 2. Using the plumb bob, mark the
centerline of the venting system on the
ceiling and drill a small hole through the
ceiling and roof at this point. From the
roof, locate the drill hole and mark the
outline of the Cathedral Ceiling Support
Box.
Step 3. Remove shingles or other
roof covering as necessary to cut the
rectangular hole for the Support Box
(refer to Table 1 for dimensions). Cut
the hole 1/8-inch larger than the
Support Box outline.
Step 4. Lower the Support Box through
the hole in the roof until Support Box
protrudes at least 2-inches below the
low side of the ceiling (Fig. 20). Align
the Support Box both vertically and
horizontally with a level. Temporarily
tack the Support Box in place through
the inside walls and into the roof
sheathing.
Step 5. Using tin snips, cut the Support
Box from the top corners down to the
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trimmed as needed (Fig. 21). Before
nailing it to the roof, run a bead of non-
hardening sealant around the Support
Box, to make a seal between the
Support Box and the roof. Clean out
any combustible material from inside the
Support Box.
Step 6. Follow Steps 4 and 5 (page 14)
of the Vertical Installation Instructions.
Step 7. Place the Support Clamp
(provided with the Support Box) inside
the Support Box (at the bottom), and
CATHEDRAL
CEILING
SUPPORT BOX
Figure 20
Figure 21
OVERLAP
CATHEDRAL
CEILING
SUPPORT
BOX
Figure 22
LEVEL
2' MIN
BELOW
FINISHED
CEILING
CUT HOLE 1/8"
LARGER THAN
SUPPORT BOX
CEILING
TRIM
SCREWS
17