(1) The clearance between masonry or concrete chimneys and combustible framing material shall be not less than,
(a) 50 mm for interior chimneys, and
(b) 12 mm for exterior chimneys.
(2) A clearance of not less than 150 mm shall be provided between a cleanout opening and combustible material.
(3) Combustible flooring, subflooring and ceiling finishes shall have not less than a 12 mm clearance from masonry or concrete chimneys.