(1) Not less than a 100 mm clearance shall be provided between the back and sides of a solid fuel-burning fireplace and combustible framing, except that a 50 mm clearance is permitted where the fireplace is located in an exterior wall.
(2) Not less than a 50 mm clearance shall be provided between the back and sides of the smoke chamber of a solid fuel-burning fireplace and combustible framing, except that a 25 mm clearance is permitted where the fireplace is located in an exterior wall.
Article 9.22.9.3. Ontario Regulation 332/12 Building Code, Information published by oncodes.ca for educational purposes only.