29 04, 2021

What procedures are to be followed when Canadian lumber is used in a structure required to have a building permit and it has not been grade stamped?

2021-04-29T17:20:27-04:00April 29th, 2021|

In Canada, every piece of structural lumber has a CLSAB approved grade stamp placed approximately 18 inches (45 cm) from one end.  The homeowner or builder will need to contact and make arrangements with a CLSAB Accredited Agency (https://www.clsab.ca/clsab-accredited-agencies/) for the Agency to grade the lumber according to the NLGA grade rule that satisfies the building code requirements.  The Agency will provide a written opinion on every piece of lumber in the structure.  The CLSAB Accredited Agency is restricted to providing a written opinion as grading requires all 6 edges of each piece of lumber to be examined, this is [...]

29 04, 2021

Can homeowners and builders use lumber imported into Canada to build residential structures?

2021-04-29T17:20:27-04:00April 29th, 2021|

Yes, if the lumber is D.Fir-L or Hem-Fir grown in the United States and stamped with an American Lumber Standards Committee Accredited Agency grade stamp (http://alsc.org/uploaded/LumberProgram_facsimile%20January%202021.pdf) as CSA-O86 provides this equivalency.  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 (https://www.clsab.ca/clsab-accredited-agencies/) to ensure the material meets the required NLGA grade.

29 04, 2021

Do timbers, which have a thickness of 5 inches and greater and used in a structure requiring a building permit, require a grade stamp?

2021-04-29T17:20:27-04:00April 29th, 2021|

Yes, however, as timbers are generally exposed in a building, they can be end stamped, or a “certificate of inspection” may be issued by a facility registered with a CLSAB Accredited Agency.  The certificate should include: Certificate number, The name of the CLSAB Accredited Agency, The mill number assigned to the facility by the CLSAB Accredited Agency, The name and address of the registered facility, The name and address of the consignee, The grade of the timbers, The grade rule used to grade the timbers – generally will be NLGA, Total pieces attributed to the certificate of inspection, Total board [...]

29 04, 2021

How were the design values established for structural lumber?

2021-04-29T17:20:27-04:00April 29th, 2021|

Prior to the 1970s, the design values of Canadian dimension lumber were determined by testing small clear samples. Beginning in the 1970s, new data was gathered on full-size graded lumber, known as in-grade testing.  The in-grade testing program involved testing thousands of pieces of dimension lumber grades to destruction in order to determine their in-service characteristics.  Resulting in the establishment of new relationships between species, sizes, and grades. In the early 1980s, the Canadian lumber industry combined the in-grade testing with a major research program for bending, tension, and compression parallel to grain strength properties of 2-inch thick nominal (38 [...]

29 04, 2021

How are the design values for structural lumber monitored?

2021-04-29T17:20:27-04:00April 29th, 2021|

The National Lumber Grades Authority (NLGA) monitors structural lumber design values for the three major commercial Canadian species groupings, Spruce-Pine-Fir (S-P-F), Douglas Fir-Larch (D.Fir-L), and Hem-Fir.  Monitoring involves the collection of samples from across Canada and testing them to ensure there has not been a statistically significant change in the design values assigned to the species and grade.

29 04, 2021

What is the difference between Machine Stress Rated (MSR) lumber and visually graded lumber?

2021-04-29T17:20:27-04:00April 29th, 2021|

MSR Grade Stamp Regular Grade Stamp Based upon in-grade testing the anticipated strength properties for visually graded lumber are determined by visually assessing each piece for the presence of strength reducing characteristics such as knots, slope of grain, etc.  The strength characteristics of MSR lumber are determined by testing each piece to measure the stiffness.  MSR lumber is also visually checked for properties other than stiffness which might affect the piece.  Given that the stiffness of each piece is measured individually, MSR lumber can be assigned higher specified design strengths than visually graded dimension lumber.  This information will appear on [...]

29 04, 2021

What is fingerjoined lumber?

2021-04-29T17:20:27-04:00April 29th, 2021|

Fingerjoined lumber is structural lumber made by gluing one or more pieces of lumber end to end that has a fingerjoint cut (see Figure 1).  Glue is applied in the fingerjoint then the pieces are pushed together as the glue cures. This approach permits a large surface area to be glued together, producing a very strong bond. Fingerjoined lumber with the appropriate grade stamp can be used as a replacement for traditional dimension lumber. Figure 1. There are two Special Products Standards approved by the CLSAB for fingerjoined structural lumber: ·     SPS 1 – Fingerjoined Structural Lumber – an example [...]

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