Precision Pays: Optimizing Lumber Thickness for Higher Recovery

In the new age of technology, there are more opportunities to create more value from logs and lumber. The companies that we have worked with who have embraced some of the newer technologies have been able to survive a lot of the challenges faced with the increased exports of logs and poor lumber markets.

One of the areas that can have a positive impact on the conversion of logs to lumber is the thickness of lumber. The extra fiber that is left on a typical 4/4 board is substantial when it is calculated; for example: thickness target 1.125”, the finished green target is 1” — that equals 12.5% of the fiber that is being donated to the customer.

There is a reason for the over-thickness: variation in the saws cutting and shrinkage of the lumber while drying. As an example, 1” thick lumber with a .030” at 3 Standard Deviations means 97% of the boards could range from 0.985” to 1.015”. This would be unacceptable for minimum thickness for green lumber. When a shrinkage of 8% during drying is added to the equation, this could result in lumber that measures 0.905” thick — under the minimum of 0.9375” by 0.0325” after kiln drying.

Using the above logic, a target of 1.0325” would create 4/4 lumber where 97% of all boards would meet the minimum thickness after kiln drying. This is a recovery of 9.25% in fiber.

There are a lot of factors that may not allow this type of precision-based approach, but this should be a goal to strive towards. The constant monitoring of thickness and equipment would need to be implemented, and a culture of quality alongside production would be paramount to achieve.

If you have any questions please contact me at d.spessert@nhla.com.

RULES CHANGES At the time of publication of this article, all of the Active NHLA members should have received their ballot for Rules changes that were approved through the Rules Committee and discussed at the 2025 Convention in San Antonio, Texas.

The ballot has many items to vote on, and it is not a requirement to vote on each item if you feel that the change has no impact on your company. It is required that the principal of the company sign the ballot.

By DANA SPESSERT, Chief Inspector