Isokern Standard 36 - Two Story Stacked Installations

45
Specialty Applications - Two Story Stacked Installations
General Information:
To install one Fireplace and DM chimney system above
one another, as in a two story stacked installation, both the upper
and lower replace installations require a structurally designed
support down to footings designed by a structural engineer.
Frequently in two story stacked installations the lower
unit is supported by a slab-on-grade, whereas the upper unit is a
typical off-grade support. The off-grade slab for the upper unit
must be built with sufcient width in order to accommodate the
width of the upper replace plus the width of the by-passing
chimney system rising from the lower unit. (Figure 77)
Dimensions for each replace unit can be found on the
website at: www.earthcore.co.
The slab for the lower unit will need to be built with
enough width to provide support for the lower replace unit
plus the bearing surface for the support columns needed to carry
the offset chimney sequence of the lower system. (Figure 77)
Floor-to-Floor Height Considerations:
In order for the lower replace installation to have
enough overhead height clearance for its chimney to rise at a
thirty degree (30°) angle of offset (maximum angle of offset as
allowed by code) and bypass to one side of the rebox in the
upper location there are minimum required oor-to-oor height
dimensions. (See chart, page 45 - Dimension “F”)
The minimum oor-to-oor height required for an
installation is determined by calculating the total horizontal
distance the lower ue must travel to the left or right for it to
bypass to one side of the upper replace. (see calculating offsets
on pages 34 & 35)
The total amount of horizontal chimney offset travel
distance will be determined by two factors:
1. The width dimension of the upper unit; and
2.The horizontal distance between centerlines of the
proposed upper and lower units.
Example:
If the upper replace and the lower replace sit on the
same centerline then the required oor-to-oor dimension is at a
maximum (See Figure 78 and chart, page 45 dimension, column
“F”.)
For every 3” of horizontal distance separating the
centerlines of the upper and lower units the overall height of the
offset sequence is reduced by one offset block or by 6”.
Notes:
A raised hearth at the lower replace will increase
the minimum oor-to-oor height requirement by the height
dimension of the raised hearth.
In the interest of clarity the drawing on pages 44 and
45, (Figures 77 & 78) of the offset chimney sequence does not
show the offset block support columns as required for offset
sequences and as described on pages 33 & 34 of this manual.
FIGURE 77