The Ontario Building Code | Panel Cladding
9.27.10.3. panel Cladding
(1) OSB and waferboard applied in panels shall have all edges supported and treated with a primer or sealer.
(2) Not less than a 3 mm gap shall be provided between sheets in cladding described in Sentence (1).
(3) Vertical joints in cladding described in Sentence (1) shall be protected with batten strips or caulking when the OSB and waferboard joints are not matched.
(4) Horizontal joints in cladding described in Sentence (1) shall be lapped not less than 25 mm or shall be suitably flashed.