Preface 

This is the fourth edition of CSA S304, Design of masonry structures, using limit states design principles. It supersedes the previous editions published in 2014, 2004, under the designation CSA S304.1, and 1994, under the designation CSA S304.1 and the title Masonry Design for Buildings (Limit States Design). Prior to the limit states design edition in 1994, there were two working stress design editions, CSA S304-M84 and the first edition of CSA S304 issued in 1977 (imperial version) and 1978 (metric version). The major changes to this edition include the following: a) Large portions of the empirical design annex (Annex F) have been removed and the annex now only covers empirical design of arches. b) Simplified design methods that employ engineering principles for design of unreinforced partition walls and veneer ties have been added to Clauses 8.17 and 10.2, respectively. c) Prism testing requirements have been changed to reflect a standardized height-to-thickness ratio of 2 leading to an adjustment to masonry compressive strengths in Table 4. d) Load factors and other material provided by the National Building Code of Canada have been removed. e) The design of reinforced and unreinforced walls and columns have been changed, including changes to the effective flange width and when to ignore slenderness. f) Requirements have been revised and new figures have been added for the design of bearing, and new requirements for the design of anchors have been added, including post-installed anchors. g) Requirements have been revised for the design of fully-grouted reinforced shear walls using the simplified modified compression field theory. h) Requirements have been revised for beam design that include the removal of the χ and λ factors based on a new series of required construction procedures. i) Limits on the acceptable height-to-thickness ratio for shear walls that contain a plastic hinge have been revised. j) Throughout this Standard, technical and editorial changes have been made to correct or clarify previous requirements. CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of the Canadian Masonry Contractors Association (CMCA), Canadian Concrete Masonry Producers Association (CCMPA), and Clay Brick Association of Canada (CBAC). This Standard was prepared by the Technical Committee on Masonry Design, under the jurisdiction of the Strategic Steering Committee on Construction and Civil Infrastructure, 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 General 

This Standard specifies requirements for the structural design of unreinforced, reinforced, and prefabricated masonry structures and components in accordance with the limit states design method of the National Building Code of Canada. This Standard also provides requirements for the structural design of prestressed masonry beams, walls, and columns in accordance with the limit states design method of the National Building Code of Canada. Notes: 1) This Standard assumes that review of the structural work designed under this Standard and review of the inspection and test results required by this Standard will be carried out during construction by the designer or another suitably qualified person to determine general conformance with the design. 2) For special structures (e.g., blast-resistant structures, towers, and chimneys), users of this Standard should also refer to applicable Codes, Standards, or Guidelines for any additional requirements. 

1.2 Other masonry standards 

Requirements for mortar and grout for unit masonry, masonry connectors, and masonry construction are specified in CSA A179, CSA A370, and CSA A371, respectively. These Standards include requirements that affect the design and are required for use with this Standard. 

1.3 Vehicular bridges 

This Standard does not apply to the structural design of vehicular bridges. 

1.4 Partitions 

This Standard applies to the structural design of partitions subject to loads such as wind loads, significant internal air pressure differences, seismic loads, or large eccentric loads mounted to the wall. Some unreinforced masonry partitions subject to these loads may be designed using Clause 8.17. 

1.5 Thin veneers secured by mortar adhesion 

This Standard does not apply to the structural design of thin veneers individually secured by mortar adhesion to a structural support or to the structural design of rough stone veneer. See CSA A371 for prescriptive requirements and limitations. 

1.6 Rough (rubble) stone masonry 

This Standard does not apply to the structural design of rough (rubble) stone masonry. See CSA A371 for prescriptive requirements. 

1.7 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; "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.