Preface
This is the second edition of CSA Standard CAN/CSA-086.1, Engineering Design in Wood {Limit States Design). It supersedes the first edition (CAN3-086.1, published in 1984) and its Supplement No. 1 (published in 1987)
Unlike the first Limit States Design edition, a parallel Working Stress Design version will not be produced. The Working Stress Design Standard, CSA Standard CAN3-O86-M84, will not be updated but will also not be formally withdrawn until such time as its reference in the National Building Code and the provincial building codes is removed. Designs produced using the two Standards may be quite different in some situations. When using this CAN/CSA-086.1, the designer must not make simultaneous use of CAN3-086.
This Standard sets out minimum requirements for the design of wood buildings and other structures of normal proportions. When structures or other component members of structures are of a specialized nature, the provisions of this Standard may not be directly applicable, but minimum requirements equivalent to those set out herein should be adhered to.
When applied to buildings, CSA Standard CAN/CSA-086.1 is intended to be used in conjunction with the National Building Code of Canada (NBCC) and/or applicable provincial and municipal building codes.
This edition of CAN/CSA-086.1 has been derived using reliability based design principles, resulting in changes to design resistance factors, specified strengths and stiffnesses. Design values derived from in-grade -testing of sawn lumber have been further refined, using reliability analysis and new data. Duration of Load adjustment factors have been derived from new data and models, and the Load Sharing Factor has been replaced by a System Factor approach that recognizes varying degrees of load sharing in different assemblies. Plywood capacities for Canadian Softwood Plywood first published by way of Supplement No.1-1987 have also been convened and incorporated in the Standard with Douglas Fir Plywood.
In concert with changes to the NBCC, seismic design provisions have been introduced, including a new clause on design of shearwalls and horizontal diaphragms. Expanded coverages of nail design requirements for nailed connections and built-up compression members have been added.
A Commentary now in preparation will provide background on these changes and is expected to be available in mid-1 990.
As well as technical updating, this edition of the Standard has undergone a significant reorganization to make the various major clauses (eg, Sawn Lumber; Glued-Laminated Timber; Fastenings) more self—contained. The General Design Clause remains, but specific design provisions have been largely relocated into the materials clauses. The clause on Unsanded Plywood has been split into two and now addresses Unsanded Plywood separately from Composite Building Components.
This Standard was prepared by the CSA Technical Committee on Engineering Design in Wood underthe jurisdiction of the Standards Steering Committee on Structures (Design), and was formally approved by these Committees. It has been approved as a National Standard of Canada by the Standards Council of Canada.
The Technical Committee consists of professional engineers and wood product specialists with balanced representation from producers of wood products, consulting engineers, universities, research organizations, government, and others. The Committee received valuable advice from subcommittees on. General Design; Sawn Lumber, Poles, and Piling; Glued- Laminated Timber; Panel Products; Fastenings; Preserved Wood Foundations; and a Task Force on Seismic Design.
Scope
1.1 General
This Standard provides criteria for the structural design and appraisal of structures or structural elements made from wood or wood products including graded lumber, glued-laminated timber, unsanded plywood, composite building components, shearwalls and diaphragms. piling, pole type construction, structural fastenings, and preserved wood foundations employing the limit states design method.
