CSA A123.21:26

Description

Preface This is the fifth edition of CSA A123.21, Standard test method for the dynamic wind uplift resistance of membrane-roofing systems . It supersedes the previous editions published in 2020, 2014, 2010, and 2004. The following are the major changes to this edition: a) addition of a concrete decks requirement before component installation (see Clause 7.1.1); b) clarification of test specimen requirements for various types of roof systems (see Clause 7.2); c) development of requirements for the component alterations to the tested systems based on extensive SIGDERS experimental investigation (see Annex D); and d) additional guidelines to the increased test pressures of 11.5 kPa (240 psf) to ensure uniformity and consistency among test labs when performing the test in this Standard (see Annex F). This Standard is based on ongoing research and testing carried out at the National Research Council of Canada (NRCC). This edition is applicable to the majority of commercial roof assemblies in North America under three different categories depending on the component attachment to the substrate: adhesive-applied membrane roofing systems (AARS), mechanically attached membrane roofing systems (MARS), and partially attached (hybrid) membrane roofing systems (PARS). This Standard was prepared by the Technical Committee on Bituminous Roofing Materials, under the jurisdiction of the Strategic Steering Committee on Building Products and Systems, and has been formally approved by the Technical Committee. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group. Scope 1.1 Applicability The test methods in this Standard determine the wind uplift resistance of sheet membrane-roofing assemblies when subjected to dynamic wind load cycles. The test methods are applicable to a) adhesive-applied membrane roofing systems (AARS); b) mechanically attached membrane roofing systems (MARS); and c) partially attached (hybrid) membrane roofing systems (PARS). A roofing assembly consists of a deck and a roofing system. The roofing system includes both a membrane and components (e.g., vapour barriers or retarders, insulation, cover boards), and during testing it is subjected to a dynamic load sequence that has been developed based on wind pressure records, simulating the effects of wind on a membrane-roofing assembly. Note: The roof membrane may be designated as the plane of airtightness. 1.2 Limitations The following limitations apply to the test methods in this Standard: a) Testing in accordance with these test methods is limited to the MARS having a fastener row separation not greater than 2896 mm (114 in) and a fastener in-line spacing not greater than 610 mm (24 in). b) Testing in accordance with this test method is limited to the PARS and AARS when adhesive spacing is not greater than 610 mm (24 in). 1.3 Terminology In this Standard, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; “should” is used to express a recommendation or that which is advised but not required; and “may” is used to express an option or that which is permissible within the limits of the Standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application. 1.4 Units of measurement The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.