ONTARIO FIRE CODE
The Ontario Fire Code O.Reg 388/97) Part 2
Chimneys, flues, & flue pipes
 Chimneys, flues and flue pipes shall be inspected...
b/ when any appliance is added to it
c/ after any chimney fire
 Chimneys, flues and flue pipes shall be repaired or replaced to eliminate any structural deficiency [such as the absence of a liner] or any decay [such as cracking, settling, crumbling mortar, distortion, advanced corrosion, separation of sections or loose or broken supports]
 Chimneys, flues and flue pipes that constitute a fire hazard shall be repaired or replaced in accordance with the Building Code.
Chimneys, flues and flue pipes shall be cleaned as often as necessary to keep them free from accumulations of combustible deposits.