minimum of ¼” per foot of run toward the chimney. Smoke pipe
sections must be attached to one another with a minimum of three
sheet metal screws and sealed with hi-temperature silicone. The smoke
pipe should not contain more than two 90° elbows (45° elbows are
preferred over 90° elbows).
The chimney draft must be stable (see chart below “Basic Boiler Data for
Layout of Chimney system”.
The top of the chimney must be 3 feet (0.9 m) above the roof and 2 feet
(0.6 m) above any structure within 10 feet (3.0 m) measured
horizontally.
Barometric Damper
We recommend that you install a barometric damper. 1
Install the barometric damper directly under the mouth of the flue
line, as there is always low pressure there. 1
Basic Boiler Data for Layout of Chimney system