Measurement Systems for the Wood Products Industry

Measuring Wood and Wood Products  Measurements are much like wood quality assessment in that the measurement system used is dependent upon intended end-use.  Approaches: 1) Board foot measurements – assumes final use as lumber, although bf volume measurements are also applied to log scaling for other solid/semi-solid applications such as veneer. 2) Cubic volume measurement, e.g., ft 3 or m 3 3) Weight scaling 4) Special units for panel products

Board foot volume measurement of lumber  Assumptions: Most softwood lumber will be used for structural applications in which little to no remanufacturing will occur, other than perhaps cut-to-length. Most hardwood lumber will be used for decorative applications (non-structural) in which remanufacturing of the lumber will occur.

Lumber Scaling  Variations in the intended end use means that these types of lumber are scaled (measured) differently.  Example: Softwood dimension lumber  Nominal (“in name only”) versus actual dimensions 2” x 4” nominal is 1.5” x 3.5” actual See table A.9 of text for nominal and actual dimensions of softwood lumber for construction purposes.

What is bf volume of a softwood nominal 2” x 4” x 8’?  Ans: BF vol = (2” x 4” x 96”)/144 in 3 /bf = 768 in 3 /144 in 3 = 5.33 bf  Consider that actual volume of this piece is 1.5” x 3.5” x 96” = 504 in 3  Scaling of softwood construction lumber is based on nominal width and thickness and actual length. Length is rounded down to nearest foot, and quite commonly down to the nearest multiple of two (i.e., typical length of construction lumber would be 8, 10, 12, 14 feet, etc.).

What about hardwoods?  Nominal thickness standards are quite different than for softwood (so you could not, for example, use table A.9 to determine hardwood nominal and corresponding actual dimensions).  Example: bottom of page 331 in text, regarding nominal 1 inch hardwood lumber: Standard rough green thickness is 1 in. Standard rough kiln dried thickness is 15/16 in. Standard surfaced thickness is 13/16 in.  Scaling of hardwood lumber is based on nominal thickness, actual width, and actual length, typically rounded down to the nearest foot.

For more information, read the handout: “Forestry 280 Log and Lumber Scaling”