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SUPPORT SECTIONS: (12S-8DM)
The chimney support section is a 4-strap 12” length of pipe. A
chimney support is required at the 30-foot level above the
fireplace after a straight chimney run (see figure 17). This
support is designed to relieve the extra weight load on the
fireplace and elbows when high chimneys are installed.
PENETRATING THE ROOF:
To maintain a 2-inch clearance to the pipe on the roof with a
pitch, a rectangular opening must be cut.
STEP 1: Determine the center point through which the pipe
will penetrate the roof.
STEP 2: Determine the pitch of the roof. Pitch is the distance
the roof drops over a given span, usually 12 inches. A 6/12
pitch means that the roof drops 6 inches for each 12 inches
one measures horizontally down the roof.
STEP 3: Use the roof-opening chart (see figure 19) to
determine the correct opening length and flashing required.
STEP 4: Remove the shingles around the opening measured
and cut out this section.
STEP 5: Add the next sections of the pipe until the end
penetrates the roofline. Check to see that the proper
clearances are maintained. Extend chimney by adding sections
of double wall pipe until pipe is a minimum of 30 inches
above the highest point of the roof cutout. Termination and
chimney must extend a minimum of 36 inches above the
highest point where it passes through roof.
Figure 16 FIRESTOP INSTALLATION
IMPORTANT:
If an exposed portion of chimney is
greater than four feet above the roofline, use support wires
to keep the chimney secured. The support wires may be
attached to the outer pipe of the chimney with screws
provided the screws do not penetrate the inner flue pipe.
Figure 17 SUPPORT SECTIONS
PITCH
SLOPE
OPENING "A" MAX
USE FLASHING
(degrees)
(inches)
MODEL NO.
FLAT
0
17
V6F-8DM
0 - 6/12
26.6
19 - 1/8
V6F-8DM
6/12 - 12/12
45.0
24 - 1/4
V12F-8DM
Figure 18 TYPICAL INSTALLATION
