Vexar 368STM-1 Owners & Installation Manual page 8

Note: If there is a second story in the home,
firestop spacer 30FS-8DM will be required.
See Firestop Spacers on page 9.
PENETRATING ROOF
To maintain a 2" clearance to the pipe on a
roof with a pitch, a rectangular opening must
be cut.
1. Determine center point through which pipe
will penetrate roof.
2. Determine center point of roof. Pitch is
the distance the roof drops over a given
span, usually 12". A 6/12 pitch means that
the roof drops 6" for each 12" measured
down from roof rafters.
3. Use roof opening chart (Figure 10) to
determine correct opening length and
flashing required.
4. Remove shingles around opening mea-
sured. Cut out this section.
5. Add next sections of pipe until end pen-
etrates roof line. Check to see that proper
clearances are maintained. Extend chimney
by adding sections of double wall pipe until
pipe is minimum of 30" above highest point
of roof cutout. Termination and chimney
must extend a minimum of 36" above high-
est point where it passes through roof.
USING ELBOW OFFSETS (30E-8DM)
1. To achieve desired offset, you may install
combinations of 12", 18", 24", 36" and 48"
length of double wall pipe (see offset chart
and Figure 11).
Offset
Elbow
6' Max.
Return
Elbow
6' Max.
Offset
Elbow
Figure 11 - Typical Offset Terminations (For Systems with 2 Elbow Sets, Minimum
Height is 25 ft., Maximum Height for Any System is 40 ft.)
8
VenTing inSTallaTion
Continued
Return
Elbow
Offset
Elbow
Return
Elbow
Offset
Elbow
A
www.fmiproducts.com
IMPORTANT: If an exposed portion of chim-
ney is greater than 4 feet above roofline,
use support wires to keep chimney secured.
Support wires may be attached to outer pipe
of chimney with screws provided screws do
not penetrate inner flue pipe.
16 / " Min.
3
8
(48.3 cm)
2" Min.
(5.1 cm)
2" Min.
(5.1 cm)
PITCH SLOPE
Flat 0°
0 - 6/12 26.6°
6/12 -
45°
12/12
Figure 10 - Determine Roof Opening
2. Chimney weight above offset rests on
return elbow. Straps must be securely
nailed to rafters or joists (see Figure 12,
details A and B, page 9).
Return
Elbow
6' Max.
Ceiling
Support Pipe
12S-8DM
Offset
Elbow
6' Max.
B
30" Min.
(76 cm)
2" Min.
(5.1 cm)
Opening "A"
OPENING FLASHING
"A" MAx MODE NO.
17" 6F-8
19 / " 6F-8
1
8
24 / " 12F-8
1
4
Return
Elbow
6' Max.
6' Max.
C
56149J