11
INTERIOR INSTALLATION WITH CATHEDRAL CEILING (CONT’D)
4
Steep pitched cathedral ceilings may require the
use of a Support Extension. This piece fits down
inside the Support and can be adjusted to increase
the support’s length by up to 22”.
The extension is attached to the support using the
eight metal screws provided. Be sure there is at
least a 2” overlap where the extension joins the
support. See Figure 12
Table 6
MINIMUM SUPPORT EXTENSION
BELOW CEILING
Slope
X
0/12 - 2/12
3 1/2”
2/12 - 7/12
5 1/2”
7/12 - 12/12
6 3/4”
12/12 - 24/12
7 1/2”
24/12
12 1/12”
SUPPORT EXTENSION (CSE24)
REDUCE CLEARANCE SUPPORT EXTENSION (SE)
INSULA
FLUE
EXTENSION
SQUARE
SUPPORT
X min
INSULA
TION
FINISH TRIM
TION
be added to the support, and box exten-
sion. Approved insulation must be listed /
compliant with ASTM E136/ULC S114 as
Non-Combustible, have a melting tempera-
ture above 2000°F/1100°C, and be water
resistant with low moisture absorption.
Materials such as rockwool or mineral wool
qualify.
TO CONTINUE INSTALLATION
REFER TO FLASHING INSTALLATION ON PAGE 6.
Figure 12
6
This support is designed to be used in rooms
with cathedral ceilings (no attic space between
the ceiling and the roof). If the support is used
as a regular floor support, follow the
instructions on page 5 (refer to fig.8 for visual
reference)
Situate the chimney in a convenient location as near as
possible to the appliance outlet.
Cut and frame a hole in the roof for the support. The
sides of this hole must be vertical (Fig. 7) (see chart on
page 3)
From above, place the support in the opening. Lower it
to a convenient height.
Note: The cone portion of the support must extend
below the ceiling. The minimum horizontal
distance between the single wall stove pipe and
the ceiling is 18". It can be reduced it a listed stove
pipe is used.
Using a level, make sure the support is vertical. If the
support extends above the roof, cut it flush with the top
of the roof. Nail the support to the framed opening
using 12-3" spiral nails.
TO CONTINUE SEE PREVIOUS STEP ... ON PAGE 5
This support is similar in application
and installation as the cathedral
support (XCS). Install it using the
instructions on page 5 (refer to Fig. 9
for visual references).
SUPPORT EXTENSION (PS)
Steep pitched cathedral ceilings may
require the use of a square support
extension (PS). This piece fits down
inside the square support and can be
adjusted to increase the support's
length by up to 16".
The extension is attached to the
support using the eight (8) metal
screws provided. Be sure there is at
least a 2" overlap where the extension joins the support (see
Fig. 10).
INTERIOR INSTALLATION WITH CATHEDRAL CEILING
Figure 7
12"
HOLE
SIZE
DOWN
B
SIDES OF HOLE
MUST BE VERTICAL
ROOF SLOPE
INCHES
ACROSS
SLOPE
A
X
A - CATHEDRAL SUPPORT (XSCC)
B - SQUARE SUPPORT (XSSC)
XSSC
EXTENSION
8 METAL SCREWS
SUPPORT (SS)
2" OVERLAP
PS
1
2
3
*
CAN BE REDUCED IF A LISTED STOVE PIPE IS USED
2
SILICONE
CAULKING
STORM COLLAR
(XFC
+
)
ROOF
JOIST
SQUARE
CATHEDRAL
SUPPORT (XSSC)
FLASHING
(12) - 3" lg.
SPIRAL
NAILS
Figure 9
RAIN CAP (CC
+)
Figure 8
CHIMNEY (XL+)
FLASHING (XFA+)
* CLEARANCE
18 " MIN.
HORIZONTAL
RAIN CAP (CC+)
SILICONE
CAULKING
STORM COLLAR
(XFC+)
CATHEDRAL
SUPPORT(XSCC)
(12) 3" SPIRAL
NAILS
RAIN CAP (CC+)
Figure 8
WARNING
Approval to include additional insulation around the chim-
ney applies only within the Reduced Clearance Support
and Square Support. DO NOT attempt to field-insulate
around the pipe at any other location or within any other
uninsulated component offered by DuraVent.
