Preface
This second edition of CSA Standard B72 (now CAN/CSA-B72), Installation Code for Lightning Protection Systems, supersedes the previous edition published in 1960.
This Standard does not differ in the fundamental principles of lightning protection from the previous edition. These principles applied to the design and construction of lightning protection systems are based on the most up-to-date technical and scientific knowledge of lightning behaviour in Canada, augmented by worldwide experience in lightning protection of buildings and structures.
This Standard provides for flexibility in the design and installation of protective systems to accommodate the use of electrically continuous roofing materials and reinforcing rods. It also includes reduced pull requirements relating to roofing structures where, for example, impervious roofing membranes are used.
It is the intent of this Standard to provide for the flexibility that may be needed in design and installation of lightning protection systems without compromising safety and reliability. Should unusual conditions be encountered where application of certain or all of the requirements of this Standard appear impracticable, it is recommended that the local regulatory authority be consulted.
This Standard was prepared by the CSA Technical Committee on Lightning Protection and was formally approved by this Committee and the CSA Standards Steering Committee on Fire Safety and Fuel Burning Equipment. It has been approved as a National Standard of Canada by the Standards Council of Canada.
Scope
1.1
This Standard covers the protection from lightning of buildings such as residences, places of public assembly, and buildings of a general industrial nature, including structures with explosive or highly flammable contents. It does not cover the protection of electrical transmission and distribution systems, and communications systems.
1.2
This Standard also contains a nonmandatory section devoted to the nature of lightning and the general principles upon which lightning protection is based, so that the user of the Standard will be able to assess the need for lightning protection in the case of any given structure (see Appendix A).