The Ontario Building Code | Clay Liners
220.127.116.11. Clay liners
(1) Clay liners shall conform to CAN/CSA-A324-M, "Clay Flue liners".
(2) liners referred to in Sentence (1) shall be not less than 15.9 mm thick and shall be capable of resisting, without softening or cracking, a temperature of 1100°C.