Alberta Building Code
Chimney Flues

9.21.2.  Chimney Flues

9.21.2.1. Chimney Flue Limitation
A chimney flue serving a fireplace or incinerator shall not
serve any other appliance.

9.21.2.2. Connections of More than One Appliance
(1)  Except as required in Article 9.21.2.1, two or more
      fuel burning appliances may be connected to the
      same chimney flue, provided adequate draft is maintained
      for the connected appliances and the connections
      are made as described in Sentences (2) and (3).
(2)  Where two or more fuel burning appliances are connected
      to the same chimney flue, the appliances must
      be located on the same storey.
(3)  The connection referred to in Sentence (2) for a solid
      fuel burning appliance shall be below connections for
      appliances burning other fuels.

9.21.2.3. Inclined Chimney Flues
Chimney flues shall not be inclined more than 45° to the
Vertical.

9.21.2.4. Size of Chimney Flues
(1)  Except for chimneys serving fireplaces, the size of a
      chimney flue shall conform to the requirements of
      the appliance installation standards referenced in
      Sentence 6.2.1.4.(1) and Article 9.33.1.2.

      Sentences 6.2.1.4.(1) and 9.33.1.2 refer to CSA B365-
      10, which, in clauses 6.2.6 and 6.2.9, require the
      installer to follow the appliance manufacturer’s installation
      instructions for proper chimney size.

(2)  Where a chimney flue serves only one appliance, the
       flue area shall be at least equal to that of the flue pipe
       connected to it.

9.21.2.5. Fireplace Chimneys
The minimum size of a chimney flue serving a masonry
fireplace shall conform to Table 9.21.2.A or Table
9.21.2.B.

9.21.2.6. Oval Chimney Flues
The width of an oval chimney flue shall be not less than
two-thirds its breath.

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