3.2.3.8.Protection of Exterior Building Face

(1) Except as permitted by Sentence (3) and in addition to the requirements of Sentences 3.2.3.7.(1) and (2) and where the maximum permitted area of unprotected openings is greater than 10% of the exposing building face, foamed plastic insulation used in an exterior wall of a building more than 3 storeys in building height shall be protected on its exterior surface by (a) concrete or masonry not less than 25 mm thick, or (b) noncombustible material that complies with the criteria for testing and conditions of acceptance stated in Sentence (2) when tested in conformance with CAN/ULC-S101, “Standard Method of 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 m 2 and have no dimension less than 2.75 m, (b) the exposed surface shall 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 noncombustible protective material will remain in place and no through openings should develop that are visible when viewed normal to the face of the material, and (e) the noncombustible protective 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. (See Note A-3.1.4.1.(1))