Important Notice – Imported Structural Lumber and Enquiries about Plywood and OSB

To: Canadian Building Associations and Officials, CLSAB Accredited Agencies and CLSAB Staff

From: Chuck Dentelbeck, President & CEO, CLSAB

Date: July 8, 2021

Subject: Imported Structural Lumber and Enquiries about Plywood and OSB

The price and availability of lumber is introducing a lot of creativity around sourcing products.
Every piece of structural lumber needs to be stamped with a CLSAB approved grade mark. This requirement appears in in CSA-O141 Softwood Lumber where it states:
Softwood lumber may be designated as Canadian Standard Lumber if the following conditions are met:
a) The lumber complies with the minimum requirements of CSA-O141.
b) The lumber is graded in accordance with grading rules approved by an accreditation board (CLSAB).
c) The lumber is inspected and identified in accordance with the regulations of that accreditation board (CLSAB).
The two exceptions to the foregoing are as follows:
1. D.Fir-L or Hem-Fir grown in the United States and stamped with an American Lumber Standards Committee Accredited Agency grade stamp as CSA-O86 provides this equivalency.
2. For all other imported lumber, the homeowner or builder must consult with a structural engineer to determine design values for the lumber and then each piece must be inspected by a CLSAB Accredited Agency to ensure the material meets the required NLGA grade.
If you have questions about plywood or OSB, the APA – The Engineered Wood Association ( is the organization to contact. The APA Help Desk can be contacted by email at or by phone at 253-620-7400 from Monday to Friday, 7 am – 4 pm PST. The Help Desk can answer basic questions, if not, they’ll escalate to Field Services or Technical Services.
If you have questions about this memorandum, do not hesitate to contact me at or 613-482-2480

Click here for printable copy of the memo