Preface
This is the second edition of CSA S502, Managing changing snow load risks for buildings in Canada’s North. It supersedes the previous edition published in 2014.
The objective of this Standard is to inform communities on measures for safe roof snow removal from existing buildings and for protection of building occupants and assets from overloading risks due to increasing accumulations and weights. Procedures that can reduce risks for roof and building collapses are outlined, including procedures for monitoring heavy snow and ice accumulations, safe removal of snow on roofs when needed, and for maintenance and snow removal planning.
The following are the major changes to this edition:
a) reviewed snow overload planning and maintenance practices;
b) strengthened requirements on detection, monitoring, and assessment of snow overloading risks for buildings;
c) reviewed all Annexes and converted Annex A into an informative annex and Annex C into a normative annex;
d) added new Annex D on roof snow overload indicators and new Annex J on managing changing snow loads infographics; and
e) updated the climate change discussion in Annex G.
CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of Standards Council of Canada, as part of the Northern Infrastructure Standardization Initiative, supported by the Government of Canada’s Clean Air Agenda.
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 General
This Standard provides
a) maintenance procedures to reduce snow overload risk on existing buildings;
b) monitoring, detection, and assessment methods for snow load risks on buildings; and
c) procedures for snow removal.
A commentary to this Standard is provided in Annex A.
1.2 Exclusions
This Standard does not address
a) specific requirements for the design or construction of new buildings subjected to snow loads; or
b) requirements for the structural rehabilitation or decommissioning of buildings subjected to critical snow overloading risks.
Note: Although provisions in the building codes apply for new design, Annex G provides supplementary background information on climate change and its implications on the design and retrofit of buildings.
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.
