2'-0"
3'-0" MIN.
ROOF RIDGE
WORK POINT
CRICKET
CHIMNEY
SECTION
THRU ROOF
LESS THAN 10'-0"
10'-0"
2'-0"
3'-0" MINIMUM
WORK
POINT
CRICKET
SECTION
THRU ROOF
CHIMNEY
54
DM 54 Chimney System: Height Requirements
Chimney Height Requirement:
The required minimum chimney height above the roof
and adjacent walls and buildings is specied by all major build-
ing 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 (Figure 110).
(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 (Figure 111).
(3) In all cases, the chimney cannot be less than 3’ above the
roof at the edge of the chimney (Figure 112 & 113).
A simple example of this would be if the roof is at
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 114)
Note: The “2 foot in 10 foot rule” is necessary in the interest
of re safety but does not ensure smoke-free operation of the
replace. Trees, buildings, adjoining roof lines, adverse wind
conditions, etc. may require a taller chimney for the replace to
draft properly.
Chase Enclosures: DM 54 chimneys can be enclosed within a
wood framed chase at zero clearance to wood framing members.
Chase enclosures need to be built to local wind load require-
ments and shall be structurally independent of the Isokern chim-
ney. As with all chimney installations, avoid overhead obstruc-
tions such as trees, power lines, etc.
CAUTION: If insulation is used in chase walls the replace
and chimney must not be placed directly against it and must be
kept a minimum 3” from all replace and chimney components.
It is recommended that where replace and chimney chases are
insulated or have vapor barriers that the inside face of the chase
rst be covered with gypsum board, plywood, particle board or
other sheathing material to assure that insulation and vapor bar-
riers remain in place and a minimum 3” away from the unit.
WARNING: Do not pack insulation around the Standard re-
place or chimney. Do not insulate the chase cavity with blown or
loose-ll type insulation materials.
Chase Top Flashings:
Non-combustible, weather tight chase ashing must be
used to cover the top of the chimney chase. Be sure to seal the
joint where the DM 54 liner passes through the chase top ash-
ing for positive weather seal. Chase ashings may be supplied
by others.
FIGURE 110
FIGURE 111
FIGURE 112
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