(1)
This Section applies to,
(a)
rectangular masonry or concrete chimneys not more than 12 m in height serving fireplaces or serving appliances having a combined total rated heat output of 120 kW or less, and
(b)
flue pipes serving solid fuel-burning appliances.
(2)
Reserved.
(3)
Except as provided in Sentence 9.21.1.3.(1), chimneys (other than those described in Sentence (1) and Sentence 9.21.1.2.(1)), gas vents and flue pipes serving gas-, oil- or solid fuel-burning appliances and associated equipment shall conform to Section 6.3.