Finalizing
the
Installation
(for qualified installers only)
17
© Travis Industries
4161018
100-01436
Air Cool Chimney - Offset Requirements (30° Elbows)
Offsets (using a pair of 30° elbows) may be used to
redirect the chimney. Typically this is done to avoid
structures, align the pipe with framing, or to gain
clearance to combustibles (see illustration below).
A maximum four 30° elbows may be used.
Each elbow must be used in conjunction with a return
elbow (so the chimney returns to a vertical direction)
If using a single offset (two 30° elbows) a maximum of
8' of inclined chimney may be used between elbows.
If using two offsets (four 30° elbows) a maximum of 4'
of inclined chimney may be used between each set of
elbows.
For every 6' of inclined chimney a flue support is
required – follow the chimney manufacturer’s
instructions for supporting the chimney.
Elbows may be used directly off the top of the fireplace.
Firestops
Whenever the chimney penetrates a floor or ceiling a
firestop is required on the bottom side of the floor joists
(see illustration below).
When passing through an attic the firestop must be
placed on the attic side of the joists
When the chimney passes through a living space it
must be totally enclosed (maintain the minimum 2"
clearance to combustibles)
The space between frames that hold the firestop in
place should be measured as follows:
Space Between Frames = 16”
Space
between
frames
Firestop
Maximum 8' Chimney Section
(4' if two pairs of 30° elbows
used)
Chimney must be totall enclosed
when passing through a living space
(make sure to include 2" (51mm)
clearance).
Chimney Offset Chart
8” Air Cooled Chimney
Inclined
Pipe
Length
Offset Rise
0 4
16
3/8
12
9 ¼
25 ½
18
12 ¼
30 ¾
24 15
¼ 36
36
21 ¼
46 ¼
48
27 ¼
56 ¼
48+12
32 ½
65 ¾
48+18 35
½ 71
48+24
38 ½
76 1/8
48+36
44 ½
86 ½
48+48 50
½ 97
For each chimney section in the offset
(between the elbows), there must be an
Elbow Strap, Tee Support, or similar
support method to support the weight of
the pipe and to relieve stress on the
elbows.
