Chimney Component Calculations; Special Offset Instructions; Offset Through Floor/Ceiling; Offset Calculations - Superior BCF-3885 Installation Instructions Manual

CTD
18"
24"
24"
Figure 32
This suggestion is provided in the interest of
better operation. If the terminations are located
too close to each other, smoke may migrate
from one flue into the other.

CHIMNEY COMPONENT CALCULATIONS

The minimum installed height of the BRF-3875
and BCF-3885 Series Fireplace Systems is 12'.
The minimum installed height of the BRF-4375
and BCF-4385 Series Fireplace Systems is 15'.
The maximum height for all systems is 80'.
To determine the number of chimney sections
and chimney components required, follow
these steps:
1. Determine total vertical height of the fireplace
installation. This dimension is the distance from
the surface the fireplace sets on to the point
where smoke exits from the termination.
2. Determine the number of chimney compo-
nents required, except chimney sections. This
would include firestop spacers, stabilizers, roof
flashing, etc.
3. The effective heights of the components are:
The Fireplace =
SS Starter Section =
FTF8/10-12 =
FTF8/10-18 =
FTF8/10-36 =
FTF8-48 =
FTF8/10-CTD Termination =
FTF8/10-CT1 Termination =
FTF8/10-CT2 Termination =
FTF8/10-CTDT Termination =
FTF8/10-S4 Stabilizer * =
* Required for every 30' of vertical chimney
and/or 10' of offset chimney.
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.)
18"
Reference Vertical Elevation Chart and deter-
mine the number of chimney sections (quantity
and length) required.

SPECIAL OFFSET INSTRUCTIONS

Chimney 30 Offset through Floor or Ceiling
It may be necessary to assemble the chimney at
30 when passing through the floor or ceiling
area. Use the F8FS30-2 firestop spacer as shown
in Figures 33 and 34 . Support the chimney at
floor or ceiling penetration with a FTF8 stabi-
lizer if distance of chimney below ceiling is 10'
or more. Maintain 2" minimum air space to
combustibles from chimney sections.
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.
When offsetting directly off the 43" systems,
always use a FTF10-30 offset elbow. A starter
section, Model BC8-SS or FTF8-SS, must then
be used as a transition to the BC8 or FTF8
chimney system.
F8FS30-2
Firestop Spacer
2" Min.
Air Space
38"
19 "
Figure 33
10 "
16 "
34 "
F8FS30-2
46 " Firestop Spacer
4"
12" to 18"
15" to 23"
2" Min.
Air Space
12" to 18"
3"
Figure 34
NOTE: DIAGRAMS & ILLUSTRATIONS NOT TO SCALE.
Attic Space
2" Min.
Air Space
FTF8-S4 Stabilizer
10'
Max.
30 Firestop
And Attic Above
Room Above
2" Min.
Air Space
FTF8-S4 Stabilizer
30 Firestop
10'
Max. And Room Above
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 ( see
Figure 35 ). The stabilizer support straps must
be attached under tension (in shear) to struc-
tural framing members above. When two sets
of elbows are used, the maximum combined
length of chimney used between elbows can-
not exceed 20' ( see Figure 36 ). Example: If C
= 10' then C cannot exceed 10'.
2
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
metal screw located at the underside of the
joint ( see Figure 37 ).
A " diameter hole must be drilled in the
chimney joint using a " diameter drill. Hole
should be drilled in center of joint overlap ( see
Figure 38 ). 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 sys-
tem exceeds 25'.
Return elbow support straps must be securely
attached under tension (in shear) to structural
framing members above. Do not substitute a
FTF8/10-30 offset elbow in place of a FTF8/10-
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.
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.
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 21 and 22 and stabi-
lizers as shown in Figure 26 .
1
" sheet
11