Connectors for Masonry
This is the first edition of CSA Standard CAN3-A370—M, Connectors for Masonry, and it is the first Canadian standard confined exclusively to the subject of masonry connectors.
Most of the current building code rules governing connectors for masonry originated several decades ago and were intended for relatively low buildings with massive solid bearing walls. Masonry bonding units were commonly used to connect walls together, and heavy steel anchors for structural members were easily accommodated in the masonry mass.
There are today a number of new developments that have necessitated reassessment of connectors in masonry design, for example:
(a) the development of masonry design based on engineering analysis has produced tall masonry buildings with very slender Walls stressed to much higher levels than a few years ago. A need has arisen for special connectors that can be built into these thin walls and can resist specific forces;
(b) more stringent requirements for wind and seismic design have focused attention on the need for effective connectors that can literally hold buildings together In the face of strong lateral and uplift forces;
(c) masonry is now being used in ways not foreseen by many building codes eg, masonry veneer secured to metal studs in high- rise buildings. Such novel uses generate a need for specialized connectors;
(d) the current need to reduce the heat loss in building envelopes has resulted in a demand for wider cavities in masonry walls to accommodate more insulation. This, in turn, has given rise to a search for special ties that will be effective in wider cavities, which will, in turn, necessitate the development of new design rules for the walls themselves; and
(e) major cladding failures that can be traced to the inadequate performance of connectors are being reported with increasing frequency in recent years. In many instances, rapid corrosion of the connectors has been found to be at fault.
There is very little information in engineering literature on the strength, performance, or durability of masonry connectors. Consequently, this Standard is neither as complete nor as informative as would be desired. It is hoped that future study and research will permit publication of more comprehensive editions in the future.
Insofar as possible, this Standard attempts to present a comprehensive treatment of the subject of connectors, and it should be read in conjunction with CSA Standard CAN3-SSO4—M, Masonry Design for Buildings, and CSA Standard CAN3-A371-M, Masonry Construction for Buildings.
This Standard is written in the SI system (Ie Systéme International d’Unités). Imperial equivalents are included in Appendix F for the user’s information.
CSA Standard CAN3-A370—M, Connectors for Masonry, was prepared by the Technical Committee on Masonry Connectors under the jurisdiction of the Standards Steering Committee on Masonry and has been formally approved by these Committees. It has been approved as a National Standard of Canada by the Standards Council of Canada.
This Standard applies to the following types of masonry connectors:
(a) ties used to interconnect the wythes of a wall;
(b) ties used to attach masonry veneer to its structural backing;
(c) anchors used to connect masonry walls to intersecting walls or to other structural members; and
(d) connectors used to attach cut stone to its structural backing.
This Standard does not apply to
(a) connectors for precast concrete;
(b) connectors for prefabricated masonry panels; or
(c) fasteners used for attaching equipment or fixtures to buildings.
Design of masonry connectors for structural adequacy shall be in accordance with CSA Standard CAN3- S304—M.
Construction practice for installation of masonry connectors shall be in accordance with CSA Standard CAN3—A371-M.