The Ontario Building Code | Protection of Exterior Building Face
3.2.3.8. Protection of exterior Building Face
(1) Except as permitted by Sentence (3) and in addition to the requirements of Sentence 3.2.3.7.(1) and where the maximum permitted area of unprotected openings is greater than 10% of the exposing building face, foamed plastic insulationhttp://thehandyforce.com/insulation/" title ="Toronto home insulation">insulation used in an exterior wall of a building more than 3 storeys in building heightshall be protected on its exterior surface by,
(a) concrete or masonry not less than 25 mm thick, or
(b) noncombustiblematerial that complies with the criteria for testing and conditions of acceptance of Sentence (2) when tested in conformance with CAN/ULC-S101, "Fire Endurance Tests of Building Construction and Materials".
(2) The criteria for testing and the conditions of acceptance for a wall assembly to satisfy the requirements of Clause (1)(b) are that,
(a) the fire exposed area of the wall assembly shall be not less than 9.3 m2 and have no dimension less than 2.75 m,
(b) the exposed surface will include typical vertical and horizontal joints,
(c) the test shall be continued for not less than 15 min and the standard time/temperature curve of the referenced standard shall be followed,
(d) the noncombustibleprotective material will remain in place and no through openings will develop that are visible when viewed normal to the face of the material, and
(e) the noncombustibleprotective material will not disintegrate in a manner that would permit fire to propagate along the surface of the test assembly.
(3) The requirements of Sentence (1) are waived for wall assemblies that comply with the requirements of Article 3.1.5.5.