29
Earthcore Industries
MAGNUM Series Fireplace
29
10’-0”
LESS THAN 10’-0”
CRICKET
3’-0” MIN
ROOF RIDGE
WORK POINT
SECTION
THRU ROOF
CHIMNEY
2’-0”
WORK
POINT
CRICKET
CHIMNEY
3’-0” MIN
SECTION
THRU ROOF
2’-0”
3’-0” MIN
Chimney Height Requirements
The DM chimney component weights are as follows:
Small crown cap:
80 lb.
Large crown cap:
100 lb.
Brick ledge:
110 lb.
6" Inner Liner:
19 lb.
12" Inner Liner:
45 lb.
Outer Casing:
90 lb.
Offset block*:
110 lb.
*Construction of an offset block sequence will shift a
portion, if not all of the chimney load off of the firebox
and smoke dome. Additional reinforced concrete footing
and slab area may need to be provided adjacent to or
as a continuation of the primary support slab area for
bearing the steel or masonry support required for an
offset sequence. (See pages 30-31) Consult a structural
engineer for specific, individual structural requirements.
The required minimum chimney height above the roof
and adjacent walls and buildings is specified by all major
building codes and is summed up in what is known as
“the 2 foot in 10-foot rule:"
1.
If the horizontal distance from the roof ridge to the
opening of the chimney is less than 10’, the top of
the chimney must be at least 2’ above the roof ridge.
2.
If the horizontal distance from the opening of the
chimney to the roof ridge is more than 10’ then a chimney
height “work point” is established on the roof surface
10’ horizontally from the opening of the chimney. The top
of the chimney must be at least 2’ above this work point.
3.
In all cases, the chimney cannot be less than 3’ above
the roof at the edge of the chimney
(Figures 28 & 29)
.
A simple example of this would be if the roof is flat, then
the chimney would need to be at least 3’ above the roof
surface. Or, if the chimney penetrates the roof at the
ridge, then the chimney must be at least 3’ above the
ridge
(Figure 30)
.
NOTE:
The “2 foot in 10-foot rule” is necessary in the
interest of fire safety but does not ensure smoke-free
operation of the fireplace. Trees, buildings, adjoining roof
lines, adverse wind conditions, etc. may require a taller
chimney for the fireplace to draft properly.
As with all chimney installations, avoid overhead
obstructions such as trees, power lines, etc.
FIGURE 28
FIGURE 29
FIGURE 30
