PLUMBLINE
PLUMBLINE
MEASURE
TRAVEL
DISTANCE
OVERHEAD
OBSTRUCTION
TRAVEL
DISTANCE
50
DM 54 Chimney System: Offset Block (cont.)
Notes:
Always support the last offset block in a sequence for
full support of the DM 54 chimney where it returns to vertical.
Support columns often carry the majority of the total
load of the vertical chimney that is set onto the last offset
block.
The total chimney weight above the last offset block
will be the total weight of the vertical chimney plus any
additional allowable loads such as the Isokern brickledge, its
related brick or stone veneers, and any crown caps, clay pots
or other masonry chimney terminations.
Be sure the foundation under all support columns is
made of concrete or steel and designed to support the loads
applied to it.
Check with local codes and a structural engineer to
confirm loading and foundation requirements.
Chimney runs are limited to one offset sequence per
chimney system.
Maximum horizontal distance of offset is six feet (6’)
and represents twenty-four offset blocks in sequence.
By code the maximum angle of offset for chimney
system is 30° off of vertical.
DM 54 Brick Ledge:
The DM 54 brickledge is a 3” thick, 32-1/2” square,
steel reinforced, concrete and pumice slab (Figure 102).
It provides a 5” ledge at all four sides of the outer casing
block and is designed to support masonry veneers to DM
54 chimneys starting below the rafters and continuing to
termination. (Figure 103)
The component is cast with an octagonal hole in its
center so that the DM 54 octagonal inner liner can pass through
it.
The brickledge has four 2-1/2” holes through it that
align with the hole in each of the four corners of the DM
54 outer casing block. These four holes are provided for
reinforcement of the chimney stack by the insertion of #4,
minimum, steel reinforcing rods and subsequent grouting.
(Figure 104)
The brickledge is intended for use in chimneys that
rise through the roof only where all four sides of the chimney
are bounded by the roof.
WARNING:
To maintain structural performance the DM 54
brickledge must not be cut or altered in any way.
FIGURE 100
FIGURE 101
