NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
12
Step 2.
Use “Height of Chimney Only” column
in The Vertical Elevation Chart to determine
combinations of chimney used above return
elbow to achieve desired heights. Reference
Components Effective Height Chart in vertical
elevation chart section.
4.
Determine amount of chimney height re-
quired by subtracting total combined height of
all pre-selected components (fireplace and
chimney components from total desired height.)
Reference Vertical Elevation Chart and deter-
mine the number of chimney sections (quantity
and length) required.
SPECIAL OFFSET INSTRUCTIONS
To clear any overhead obstructions, you may
offset your chimney system using Security's
30
°
offset and return elbows. Use two elbows -
an offset elbow to initiate the offset and a return
elbow to terminate it. A 30
°
offset elbow, an-
gling in any direction, may be the first compo-
nent used off the top of the fireplace flue collar.
The offset and return elbows may be attached
together, or a section or sections of chimney
may be used between, but do not exceed 20' in
total length between elbows. If sections of pipe
exceed 10' between elbows, a chimney stabilizer
must be used at the midpoint (
Figure 37 ). The
stabilizer support straps must be attached under
tension (in shear) to structural framing mem-
bers above. When two sets of elbows are used,
the maximum combined length of chimney used
between elbows cannot exceed 20' (
Figure 38 ).
Example:
If C
1
= 10' then C
2
cannot exceed 10'.
If an offset exceeds 6' in length, each chimney
joint beyond the first 6' of offset to the return
elbow, must be secured by a No. 8 x
¹⁄₂
" sheet
metal screw located at the underside of the joint
(
Figure 39 ).
A
¹⁄₈
" diameter hole must be drilled in the chim-
ney joint using a
¹⁄₈
" diameter drill. Hole should be
drilled in center of joint overlap (
Figure 40 ). Be
sure to drill only through the outer chimney
casting. Do not puncture the inner flue.
Maximum offset of chimney system is 30
°
.
Two offsets must not be assembled to form a
60
°
offset. However, two sets of offset and
return elbows may be used on a single flue
system, provided the total height of the system
exceeds 25'.
Return elbow support straps must be securely
attached under tension (in shear) to structural
framing members above. Do not substitute a
FTF8-30 offset elbow in place of a FTF8-E30
return elbow.
OFFSET CALCULATIONS
Step 1.
Use Offset Chart to determine amount
of horizontal offset (A) and height (B) for vari-
ous chimney section assemblies.
FTF8 VERTICAL ELEVATION CHART
Step 3.
Use Elevation Chart as job estimator
only. Add necessary firestop spacers and stabi-
lizers as required. Firestop spacers must be
used as shown in
Figures 23 and 24 and stabi-
lizers as shown in
Figure 29.
Height Of
Number Of FTF8
Chimney Only
Chimney Lengths
Inches
Feet/Inches
12" 18"
36" 48"
Height Of
Number Of FTF8
Chimney Only
Chimney Lengths
Inches
Feet/Inches
12" 18"
36" 48"
386
¹⁄₂
32
2
¹⁄₂
0
1
0
8
390
³⁄₄
32
6
³⁄₄
2
0
0
8
396
³⁄₄
33
0
³⁄₄
1
1
0
8
404
¹⁄₂
33
8
¹⁄₂
0
0
1
8
414
³⁄₄
34
6
³⁄₄
1
0
1
8
416
¹⁄₂
34
8
¹⁄₂
0
0
0
9
420
³⁄₄
35
0
³⁄₄
0
1
1
8
426
³⁄₄
35
6
³⁄₄
1
0
0
9
432
³⁄₄
36
0
³⁄₄
0
1
0
9
437
36
5
2
0
0
9
443
36 11
1
1
0
9
450
³⁄₄
37
6
³⁄₄
0
0
1
9
461
38
5
1
0
1
9
462
³⁄₄
38
6
³⁄₄
0
0
0
10
466
³⁄₄
38 10
³⁄₄
0
1
1
9
472
³⁄₄
39 4
³⁄₄
1
0
0
10
478
³⁄₄
39 10
³⁄₄
0
1
0
10
483
40
3
2
0
0
10
489
40
9
1
1
0
10
496
³⁄₄
41
4
³⁄₄
0
0
1
10
507
42
3
1
0
1
10
508
³⁄₄
42
4
³⁄₄
0
0
0
11
513
42
9
0
1
1
10
519
43
3
1
0
0
11
525
43
9
0
1
0
11
529
¹⁄₄
44
1
¹⁄₄
2
0
0
11
535
¹⁄₄
44
7
¹⁄₄
1
1
0
11
543
45
3
0
0
1
11
553
¹⁄₄
46
1
¹⁄₄
1
0
1
11
555
46
3
0
0
0
12
559
¹⁄₄
46
7
¹⁄₄
0
1
1
11
565
¹⁄₄
47
1
¹⁄₄
1
0
0
12
571
¹⁄₄
47
5
¹⁄₄
0
1
0
12
575
¹⁄₂
47 11
¹⁄₂
2
0
0
12
581
¹⁄₂
48
5
¹⁄₂
1
1
0
12
589
¹⁄₄
49
1
¹⁄₄
0
0
1
12
599
¹⁄₂
49 11
¹⁄₂
1
0
1
12
601
¹⁄₄
50
1
¹⁄₄
0
0
0
13
605
¹⁄₂
50
5
¹⁄₂
0
1
1
12
611
¹⁄₂
51 11
¹⁄₂
1
0
0
13
617
¹⁄₂
51
5
¹⁄₂
0
1
0
13
621
¹⁄₂
51
9
¹⁄₂
2
0
0
13
627
¹⁄₂
52
3
¹⁄₂
1
1
0
13
635
¹⁄₂
52 11
¹⁄₂
0
0
1
13
645
¹⁄₂
53
9
¹⁄₂
1
0
1
13
647
¹⁄₂
53 11
¹⁄₂
0
0
0
14
651
¹⁄₂
54
3
¹⁄₂
0
1
1
13
657
¹⁄₂
54
9
¹⁄₂
1
0
0
14
663
¹⁄₂
55
3
¹⁄₂
0
1
0
14
667
³⁄₄
55
7
³⁄₄
2
0
0
14
673
³⁄₄
56
1
³⁄₄
1
1
0
14
681
¹⁄₂
56
9
¹⁄₂
0
0
1
14
691
³⁄₄
57
7
³⁄₄
1
0
1
14
693
¹⁄₂
57
9
¹⁄₂
0
0
0
15
697
³⁄₄
58
1
³⁄₄
0
1
1
14
703
³⁄₄
58
7
³⁄₄
1
0
0
15
709
³⁄₄
59
1
³⁄₄
0
1
0
15
714
59
6
2
0
0
15
720
60
0
1
1
0
15
727
³⁄₄
60
7
³⁄₄
0
0
1
15
738
61
6
1
0
1
15
739
³⁄₄
61
7
³⁄₄
0
0
0
16
744
62
0
0
1
1
15
11
0 11
1
0
0
0
17
1
5
0
1
0
0
21
¹⁄₄
1
9
¹⁄₄
2
0
0
0
27
¹⁄₄
2
3
¹⁄₄
1
1
0
0
35
2 11
0
0
1
0
47
3 11
0
0
0
1
51
¹⁄₄
4
3
¹⁄₄
0
1
1
0
57
¹⁄₄
4
9
¹⁄₄
1
0
0
1
63
¹⁄₄
5
3
¹⁄₄
0
1
0
1
67
¹⁄₄
5
7
¹⁄₄
2
0
0
1
73
¹⁄₄
6
1
¹⁄₄
1
1
0
1
81
¹⁄₄
6
9
¹⁄₄
0
0
1
1
93
¹⁄₄
7
9
¹⁄₄
0
0
0
2
97
¹⁄₄
8
1
¹⁄₄
0
1
1
1
102
¹⁄₂
8
6
¹⁄₂
1
0
0
2
109
¹⁄₄
9
1
¹⁄₄
0
1
0
2
113
¹⁄₂
9
5
¹⁄₂
2
0
0
2
119
¹⁄₂
9 11
¹⁄₂
1
1
0
2
127
¹⁄₄
10
7
¹⁄₄
0
0
1
2
137
¹⁄₂
11
5
¹⁄₂
1
0
1
2
139
¹⁄₄
11
7
¹⁄₄
0
0
0
3
143
¹⁄₂
11 11
¹⁄₂
0
1
1
2
149
¹⁄₂
12
5
¹⁄₂
1
0
0
3
155
¹⁄₂
12 11
¹⁄₂
0
1
0
3
159
³⁄₄
13
3
³⁄₄
2
0
0
3
165
³⁄₄
13
9
³⁄₄
1
1
0
3
173
¹⁄₂
14
5
¹⁄₂
0
0
1
3
183
³⁄₄
15
3
³⁄₄
1
0
1
3
185
¹⁄₂
15
5
¹⁄₂
0
0
0
4
189
³⁄₄
15
9
³⁄₄
0
1
1
3
195
³⁄₄
16
3
³⁄₄
1
0
0
4
201
³⁄₄
16
9
³⁄₄
0
1
0
4
206
17
2
2
0
0
4
212
17
8
1
1
0
4
219
³⁄₄
18
3
³⁄₄
0
0
1
4
230
19
2
1
0
1
4
231
³⁄₄
19
3
³⁄₄
0
0
0
5
236
19
8
0
1
1
4
242
20
2
1
0
0
5
248
20
8
0
1
0
5
252
21
0
2
0
0
5
258
21
6
1
1
0
5
266
22
2
0
0
1
5
276
23
0
1
0
1
5
278
23
2
0
0
0
6
282
23
6
0
1
1
5
288
24
0
1
0
0
6
294
³⁄₄
24
6
³⁄₄
0
1
0
6
298
¹⁄₄
24 10
¹⁄₄
2
0
0
6
304
¹⁄₄
25
4
¹⁄₄
1
1
0
6
312
26
0
0
0
1
6
322
¹⁄₄
26 10
¹⁄₄
1
0
1
6
324
27
0
0
0
0
7
328
¹⁄₄
27
4
¹⁄₄
0
1
1
6
334
¹⁄₄
27 10
¹⁄₄
1
0
0
7
340
¹⁄₄
28
4
¹⁄₄
0
1
0
7
344
¹⁄₂
28
8
¹⁄₂
2
0
0
7
350
¹⁄₂
29
2
¹⁄₂
1
1
0
7
358
¹⁄₄
29 10
¹⁄₄
0
0
1
7
368
¹⁄₂
30
8
¹⁄₂
1
0
1
7
370
¹⁄₄
30 10
¹⁄₄
0
0
0
8
374
¹⁄₂
31
2
¹⁄₂
0
1
1
7
380
¹⁄₂
31
8
¹⁄₂
1
0
0
8
