FMI S42 - Manual (Page 8)

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VENTING INSTALLATION
Continued
Figure 9 - Elbow Offset
B
A
Screws
FIRESTOP SPACERS (FS-8DM)
Firestop spacers are required at each point
where the chimney penetrates a floor space.
Their purpose is to establish and maintain
the required clearance between the chimney
and the combustible materials. When the pipe
passes through a framed opening into a living
space above, the firestop must be placed onto
the ceiling from below as shown in Figure 10.
They also provide complete separation from
one floor space to another or attic space as
required by most codes. When the double wall
pipe passes through a framed opening into an
attic space, the firestop must be placed into an
attic floor as shown in Figure 11.
Figure 10 - Firestop Spacer with Living
Space Above Ceiling
Figure 11 - Firestop Spacer with Attic
Space Above Ceiling
Existing
Ceiling
Frame
Firestop
Spacer
Screws or
Staples
(Min. of 8)
Firestop
Spacer
Screws or Staples
(Min. of 8)
PENETRATING ROOF
To maintain a 1" clearance to the pipe on a
roof with a pitch, a rectangular opening must
be cut.
1. Determine the center point through which
the pipe will penetrate the roof.
2. Determine the center point of the 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"
one measure horizontally down from the
roof rafters.
3. Use the roof opening chart (Figure 12,
page 9) to determine the correct opening
length and flashing required.
4. Remove the shingles around the opening
measured. Cut out this section.
5. Add the next sections of the pipe until the
end penetrates the roof line. Check to see
that the proper clearances are maintained.
Extend chimney by adding sections of
double wall pipe until pipe is minimum of
30" above the highest point of the roof cut-
out. Termination and chimney must extend
a minimum of 36" above the highest point
where it passes through the roof.
Existing
Ceiling
Frame
Figure 8 - Ceiling Support Pipe
12S-8DM
2" Min.
Straps
Straps
Straps
Straps
Detail A
Return Elbow
Detail B
Angle Firestop
See Detail A
See Detail B