TOA Electronics CST38MH - Manual (Page 13)

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
13
Figure 33
Ten fooT rule summary
The minimum chimney height above the roof
and/or to adjacent walls and buildings is speci-
fied by all major building codes.
If the horizontal distance from the peak of
the roof is less then 10' (3 m), the top of the
chimney must be at least 2' (610 mm) above
the peak of the roof.
If the horizontal distance from the chimney
edge to the peak of the roof is more than 10'
(3 m), a chimney height reference point is es-
tablished on the roof surface located horizontally
10' (3 m) from the chimney edge. The top of the
chimney must be at least 2' (610 mm) above
this reference point. In all cases, the chimney
cannot be less then 3' (914 mm) above the roof
at the edge of the chimney.
The 2' in 10' rule is necessary in the interest
of safety, but does not ensure smoke-free op-
eration. Trees, buildings, adjoining roof lines,
adverse wind conditions, etc., may require a
taller chimney should the fireplace not draft
properly (see Figure 33).
Less than
10' (3 m)
10' (3 m)
3' (914 mm)
Min.
2' (610 mm) Min.
3' (914 mm)
Min.
fTf8 chImney comPonenT
calculaTIons
The minimum installed height of the completed
fireplace system is 15". The maximum system
height is 80' 0".
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 termina-
tion.
. Determine the number of chimney compo-
nents required, except chimney sections.
This would include thimbles, extensions,
roof flashing, etc.
3. The effective heights of the components
are:
The fireplace = 48”
fTf8-1 = 10-1/4”
fTf8-18 = 16-1/4”
fTf8-4 = -1/4”
fTf8-36 = 34-1/4”
fTf8-48 = 46-1/4”
fTf8-cTd Termination = 6”
4 Determine amoun 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. in Table 4 on Page 15.
sPecIal offseT InsTrucTIons
To clear any overhead obstructions, you may
offset your chimney system using Security
Chimneys 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, angling in any direction, may
be the first component used off the top of the
fireplace flue collar. Maintain 2" minimum air
space to combustibles from chimney sections.
See Figures 41 and 42.