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Air-dried Lumber: Lumber that has reached its
equilibrium moisture content by being exposed to air.
Board Foot: A unit of lumber measure that is 1” thick by
12” wide by 12” long. A board 1” by 6” by
2’ equals 1 board foot. A board 2” by 12” by
12” equals 2 board feet.
Boule: A log live sawn and kept
together in the order of sawing.
Bow: A form of warp that
is an end-to-end curve along the length of the board.
Burl: a wartlike growth that forms on a tree and that, when sliced,
produces extremely disoriented grain patterns that
Cant: A log that has been debarked and sawn
Case-hardening: A drying defect where the surface
of wood dries faster than the wetter inner core; this
and stresses that release when the board is cut.
Common: (mixed 1 and 2 common) are boards that have too many defects
to be FAS or Select.
Conifer: A type of tree that’s characterized
by needle-like or scale-like foliage, usually evergreen.
Crotch: The highly figured wood that occurs where a limb joins a trunk;
the grain swirls dramatically
have crowded and twisted together.
Crook: A form
of warp that is an end-to-end curve along the edge of the board.
Cup: A form of warp that is an edge-to-edge curve across the face
of the board.
Deciduous: A type of tree where the leaves
fall off every autumn; typically a hardwood,
regions keep their leaves all year long.
checks: A drying defect caused by the ends of the boards drying
faster than the
prevented by sealing the end grain.
End-coating: The process of sealing the
ends of the boards to prevent checking
by unrestrained evaporation of moisture.
FAS: First and Second. Mixed domestic hardwood lumber grade is the
highest grade of hardwood
must be 6” or wider, 8’ or
longer. Walnut and butternut are the
Fiddleback: A type of washboardlike
figure that occurs in some species of
Figure: The pattern on a wood’s
surface, resulting from the combination
of its natural
features and the way the log was
Flitch matched or Book matched: Sequentially
sawn lumber from the same log.
6/4, etc: Is the thickness given in fractions. It implies that
sawn 1/16”+ over the stated fraction.
= 1-1/16” to 1-1/8” and
should finish to 13/16”
5/4 = 1-5/16” to 1-3/8” and
should finish to 1-1/16”
Grade: A designation of the quality of a log
or wood product such as lumber,
Grain: The direction of wood
fibers in a tree or piece of wood with the respect
Hardwood: Wood cut
from the broad-leaved, mostly deciduous trees that belong
to the botanical
wood that forms the spine of the tree.
Honeycomb: A drying defect
that occurs when the lumber undergoes severe
case-hardening in the
of drying; appears as deep, internal
Juvenile wood: The wood in every tree that
forms within its first 10 years or so; usually has undesirable
as low strength
shrinkage along the grain.
Kiln: A heated chamber
of a building used to dry lumber; humidity and air circulation
and adjusted as
the wood dries.
Kiln-dried lumber: Lumber that
has dried in a kiln to a specific moisture content.
section of a branch or limb that has been overgrown by expanding
may be loose
Moisture Content: The amount of
water in a piece of wood expressed as a percentage
weight minus the
dry weight times
by the green
Nominal dimensions: Dimensions
based on rough-cut(unplanned) softwoods; a
nominally 2” x 4”—It’s
actually 1-1/2” x 3-1/2”.
Pith: The small, soft core occurring in the
center of the tree trunk
Plain Sawn: Lumber sawn parallel to the grain.
Quatersawn Lumber: Vertical
Ray: a ribbon-shaped strand of wood
cells that extends from the inner
bark to the
the axis of a
appear as fleck
surfaces of some species.
Rift Lumber: Diagonally grained lumber.
Sapwood: New wood surrounding the
Select: A clear
board that is too short or narrow to be FAS.
Shake: A lumber
defect that is a lengthwise separation of
Line Rip One Edge
SLR2E: Straight Line Rip
cut from coniferous trees belonging
to the botanical
Spalting: An attractive dark brown or black stain
Speck: A defect
that’s caused by a fungus living
in a tree, which
appears as small white pits or spots.
Split: A separation
of wood fibers that
a piece of
at the ends.
Sticker: A piece of wood, typically
inserted at regular
layers of green
wood to assist
a stain that forms
under the stickers
in a stack of drying
stripe or ribbon
woods with interlocked
slopes in alternate
Checks: A drying defect
when the surface
dries too quickly
S2S: Surfaced Two Faces
Faces and Straight
Twist: A form
Wane: The presence
Warp: Any deviation