8
D. Dual masonry chimneys taller than 12 feet
should be tied into the surrounding structure for
additional support, due to the weight of the dual
flue system. Consult with an engineer to determine
the best way to do so for your project.
E. If chimney exit opening does not already exist
locate the point where the chimney will exit the
roof by plumbing down to the center of the fire-
place chimney. Drive a nail into the roof to mark
the center.
F. Measure to all sides of the nail and mark the
required opening, and then cut a hole in the roof.
Remember that the hole is measured on the hori-
zontal, and then projected to the roof. The hole
may then be larger, depending on the pitch of the
roof. See Figure 23.
G. Frame the opening in the roof.
H. Continue to add flue sections, extending the
chimney through the roof.
I. Install roof flashing appropriate to the roof
pitch.
J. Use mortar to create a slope away from the clay
flue, running out to the edge of the finish material,
to assist with water drainage. Install the chimney
cap following instructions provided. This will pro-
tect the chimney from rain, birds, animals and
leaves. See Figure 24.
4.2 Metal Chimney
Install the metal chimney following the instructions
below and the instructions provided by the chimney
pipe manufacturer.
Install two Stone Age masonry pipe adapters (sold
separately) to the top of the firebox, using 16” I.D.
adapters for the NA 72. Connect the first pipe sec-
tions to the metal adapters as shown in Figure 25.
Chimney plumbing can either be straight through the
ceiling and through the roof, or if the fireplace is in-
stalled on an outside wall, the chimney can be exter-
nal to the house. Affix warning labels to the pipe.
See Figure 25.
Offset
Blocks
CMU
Figure 22. Offset Blocks and CMU Support
Pipe
Adapter
Chimney
Pipe
Figure 24. Install Chimney Cap
Figure 23. Roof Penetration
Figure 25. Connect Chimney
Chimney
Pipe
Pipe
Adapter
Warning
Label
Summary of Contents for NA72IND
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