The Ontario Building Code | Heavy Timber Roof Permitted
220.127.116.11. Heavy Timber Roof Permitted
(1) Unless otherwise permitted by Articles 18.104.22.168. to 22.214.171.124., a roof assembly in a building up to 2 storeys in building height is permitted to be of heavy timber constructionregardless of building area or type of construction required, provided the building is sprinklered.
(2) If Sentence (1) permits a roof assembly to be of heavy timber construction, structural members in the storey immediately below the roof assembly are permitted to be of heavy timber construction.