Measurement Systems for the Wood Products Industry

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Transcript Measurement Systems for the Wood Products Industry

Measurement Systems for
the Wood Products Industry
Measuring Wood and Wood
 Measurements are much like wood quality
assessment in that the measurement
system used is dependent upon intended
 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
 2) Cubic volume measurement, e.g., ft3 or m3
 3) Weight scaling
 4) Special units for panel products
Board foot volume measurement of
 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
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
 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
What is bf volume of a softwood
nominal 2” x 4” x 8’?
 Ans: BF vol = (2” x 4” x 96”)/144 in3/bf =
768 in3/144 in3 = 5.33 bf
 Consider that actual volume of this piece is
1.5” x 3.5” x 96” = 504 in3
 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”