Isokern Standard 36 - Structural Information

STEEL ANGLE
4x4x3/8 MIN
FRONT DAMPER
SUPPORT
CAST IRON DAMPER
(IF USED)
STEEL ANGLE
4x4x3/8 MIN
Top Plate
41
Structural Information
The rebox/smoke dome assembly has a load capacity
that allows for the replace system to carry a limited amount of
straight, vertical DM chimney sections. The load capacity for
each model, stated as maximum DM chimney heights without
additional structural support, are listed on page 3.
These chimney heights are for straight chimneys (no
offsets) and are exclusive of the brick ledge.
Important: DM chimneys taller than the listed maximum
heights require a steel angle (minimum of 4” x 4” x 3/8”) be
set across the rebox opening when assembling the unit as a
structural lintel. Consult a structural engineer to design proper
structural support.
This steel angle shall span the rebox opening, bearing
fully on the front 4 inches of the rebox side wall components.
The vertical leg of the angle steel lintel should turn up and sit in
front of the damper plate component. (Figure 70)
Important: The application of the steel angle as described
above is also required in all replace installations where the
brick ledge is used.
This required steel lintel placement is in addition to
the reinforcing required for DM chimneys with brick ledge as
described on pages 36 and 37.
Important: For DM chimneys with both offsets and a brick
ledge it is important to fully support the last offset block where
the chimney returns to vertical. This is required in order to
provide complete vertical support for the brick ledge and its
related loads.
Important: When placing steel angles or any other steel support
members into the Fireplaces structure maintain a 2” minimum
air space around steel members for clearance to combustible
members and combustible surfaces.
Wind Load Calculations: Using the required Earthcore
Mortar to install the DM chimney system, the maximum height
above the roof line of a one story residence with an exposure
classication C without additional structural support is:
90 MPH 26’-0”
100 MPH 24’-0”
110 MPH 21’-8”
120 MPH 19’-8”
130 MPH 18’-0”
140 MPH 17’-6”
146 MPH 16’-8”
150 MPH 16’-4”
For two story residences, please call the Technical Department
at: 800-642-2920.
Important: The top plate of the rebox is not meant to be
used as a structural support of any veneer. Consult a structural
engineer for structural support of any veneer bearing weight on
the Isokern top plate for additional structural support.
FIGURE 70