IS LUMBER
QUALITY
SLIPPING?
by Robert Stroh
JLC - APRIL 1989
Lumber serves as the primary framing
material for residential and light-commercial
construction. Has lumber
changed over the years? What is the
future outlook for the lumber supply?
Answers to these questions require a
discussion of tree growth, lumber production,
lumber grading and
purchasing, and forest management.
The discussion will be on the softwoods,
from which framing lumber is
commonly produced.
Tree Growth
The center of the stem of a tree is
called the pith. Surrounding the pith
and running out to the bark is the
woody portion of the tree, which is the
source of our lumber. Unfortunately,
lumber is not a uniform material: It
contains knots, varies in density and
strength, and