Draft Details

Designation:CSA O141
Contact name:Zaeem Khalid
Review start date:Nov 29, 2022
Review end date:Jan 28, 2023
Contact email:thuy.ton(at)csagroup.org
Draft Scope/Description:


This Standard specifies requirements pertaining to the quality and uniformity of softwood lumber and establishes the designation “Canadian Standard Lumber” for lumber that meets the requirements of this Standard (see Clause 4). 

This Standard covers the following topics:

a) accreditation board and agency responsibilities (Clause 5);

b) measurement (Clause 6)

c) standard sizes (Clause 7);

d) grading rule requirements (Clause 8);

f) identification (grade stamps and certificates) (Clause 9); and

g) determination of design properties (Clause 10).

This Standard applies to lumber produced and consumed in and exported from Canada, and for lumber imported into Canada.

This Standard provides for the grading of structural lumber by both visual and mechanical means.

This Standard also includes detailed Annexes covering lumber terminology and lumber industry abbreviations.

This Standard does not cover trade practices, grades (other than grading rules and identification), the details of accreditation board and grading agency inspection procedures, or strength and related properties.

The provisions of this Standard apply to species when the species is included in rules approved by the accreditation board.  Although this Standard applies to softwood lumber, it may be applied to hardwood lumber used in applications that ordinarily use softwood lumber.


In CSA Standards,

a) “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;

b) “should” is used to express a recommendation or that which is advised but not required;

c) “may” is used to express an option or that which is permissible within the limits of the standard; and

d) “can” is used to express possibility or capability.

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.


In keeping with the practice of lumber manufacturers throughout North America, sizes in this Standard are given in board measure units, which are expressed in yard/pound units (see Section 6.1). Equivalent SI (metric) sizes, rounded to the nearest millimeter, are given in parentheses for the sake of convenience in use and in commercial transactions.  The values given in yard/pound units are the standard. The values given in parentheses are for information only.  See Annex E for a discussion of how metric dimensions have been calculated for this Standard.


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