Astria.us.com
125160-01_D
15
Figure 16 - Ceiling Support Pipe 12S-12DM
ASSEMBLY AND INSTALLATION OF DOUBLE WALL CHIMNEY
SYSTEM
Each double wall chimney section consists of a galvanized outer
pipe, a stainless steel inner flue pipe and a wire spacer. The pipe
sections must be assembled independently as the chimney is in-
stalled. When connecting chimney directly to the fireplace, the inner
flue pipe section must be installed first with the lanced side up. The
outer pipe section can then be installed over the flue pipe section
with the hemmed end up. Press down on each pipe section until the
lances securely engage the hem on the fireplace starter. The wire
will assure the proper spacing between the inner and outer pipe
sections.
Continue to assemble chimney sections as outlined above, making
sure that both the inner and outer pipe sections are locked together.
When installing double wall snap-lock chimney together, it is im-
portant to assure the joint between the chimney sections is locked.
Check by pulling chimney upward after locking. The chimney will
not come apart if properly locked. It is not necessary to add screws
to keep the chimney together (exception, see Figure 15).
VENTING INSTALLATION
Continued
OFFSET
RISE
CHIMNEY LENGTH
A
B
12" 18" 24" 36" 48"
4
3
/
8
"
16
3
/
8
"
ELBOW SET ONLY
9
3
/
4
"
25
1
/
2
"
1
12
3
/
4
"
30
3
/
4
"
1
15"
34
3
/
4
"
1
18"
40"
1
1
21
1
/
4
"
46
1
/
4
"
1
23
3
/
4
"
49
1
/
4
"
1
1
27
3
/
4
"
56
3
/
4
"
1
30"
60
3
/
4
"
1
1
33"
66"
1
36"
71"
1
1
38
1
/
4
"
75"
2
41
1
/
4
"
80
1
/
4
"
1
1
1
45"
86
3
/
4
"
2
46
3
/
4
"
89
1
/
2
"
1
1
1
51"
97"
1
1
53
1
/
4
"
101"
2
56
1
/
4
"
106
1
/
4
"
2
59
1
/
4
"
111
1
/
2
"
1
1
1
61
3
/
4
"
115
1
/
2
"
1
2
64
3
/
4
"
120
3
/
4
"
1
2
68
1
/
4
"
127"
2
1
70"
130"
1
1
2
74
1
/
4
"
137
1
/
2
"
1
2
1
76
3
/
4
"
141
1
/
2
"
1
2
1
79
3
/
4
"
146
3
/
4
"
4
OFFSET CHART (22-50 FT. SYSTEM HEIGHT)
Figure 15 - Elbow Offset
B
A
Screws
USING ELBOW OFFSETS (30E-12DM)
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 15).
2. Chimney weight above offset rests on return elbow. Straps
must be securely nailed to rafters or joists (see Figure 16,
details A and B).
3. Maximum length of pipe between supports (re-turn elbow or
12S-12DM) is 6’ of angle run. Maxi-mum of two 6’ angle run
sections per chimney system (see Figure 17, page 16).
4. All pipe connections between the offset and re turn must be
secured with two screws on the outer pipe only (see Figure 15).
Do not penetrate the inner stainless.
2
"
(51 mm)
Min.
Straps
Detail A
Return Elbow
Detail B
Angle Firestop
See Detail A
See Detail B
Straps
Straps
Straps
