Fire‑Retardant‑Treated Wood. As specified in building
codes, a wood product that has been treated with chemicals
by a pressure process or treated during the manufacturing
process for the purpose of reducing its flame spread perfor‑
mance in an ASTM E 84 test conducted for 30 min to per‑
formance levels specified in the codes.
Flake. A small flat wood particle of predetermined dimen‑
sions, uniform thickness, with fiber direction essentially
in the plane of the flake; in overall character resembling a
small piece of veneer. Produced by special equipment for
use in the manufacture of flakeboard.
Flakeboard. (See Wood‑Based Composite Panel.)
Flame Retardant. A treatment, coating, or chemicals that
when applied to wood products delays ignition and reduces
the flame spread of the product.
Flame Spread. The propagation of a flame away from the
source of ignition across the surface of a liquid or a solid, or
through the volume of a gaseous mixture.
Flat Grained. (See Grain.)
Flat Sawn. (See Grain.)
Flecks. (See Rays, Wood.)
Flitch. A portion of a log sawn on two or more faces—com‑
monly on opposite faces leaving two waney edges. When
intended for resawing into lumber, it is resawn parallel to its
original wide faces. Or, it may be sliced or sawn into veneer,
in which case the resulting sheets of veneer laid together
in the sequence of cutting are called a flitch. The term is
loosely used. (See Cant.)
Framing. Lumber used for the structural member of a
building, such as studs and joists.
Full‑Cell Process. Any process for impregnating wood with
preservatives or chemicals in which a vacuum is drawn to
remove air from the wood before admitting the preservative.
This favors heavy adsorption and retention of preservative
in the treated portions.
Furnish. Wood material that has been reduced for incorpo‑
ration into conventional wood‑based composites; including
flakes, particles, and fiber.
Gelatinous Fibers. Modified fibers that are associated with
tension wood in hardwoods.
Girder. A large or principal beam used to support concen‑
trated loads at isolated points along its length.
Gluability. (See Bondability.)
Glue. Originally, a hard gelatin obtained from hides,
tendons, cartilage, bones, etc., of animals. Also, an adhe‑
sive prepared from this substance by heating with water.
Through general use, the term is now synonymous with the
term “adhesive.”
Glue Laminating. Production of structural or nonstructural
wood members by bonding two or more layers of wood to‑
gether with adhesive.
Glued Laminated Timber (Glulam). A manufactured
structural timber product composed of layers of dimensional
lumber glued together.
Glueline. (See Bondline.)
Grade. The designation of the quality of a manufactured
piece of wood or of logs.
Grain. The direction, size, arrangement, appearance, or
quality of the fibers in wood or lumber. To have a specific
meaning the term must be qualified.
Close‑Grained (Fine‑Grained) Wood—Wood with nar‑
row, inconspicuous annual rings. The term is sometimes
used to designate wood having small and closely spaced
pores, but in this sense the term “fine textured” is more
often used.
Coarse‑Grained Wood—Wood with wide conspicuous
annual rings in which there is considerable difference
between earlywood and latewood. The term is sometimes
used to designate wood with large pores, such as oak,
keruing, meranti, and walnut, but in this sense, the term
“open‑grained” is more often used.
Cross‑Grained Wood—Wood in which the fibers deviate
from a line parallel to the sides of the piece. Cross grain
may be either diagonal or spiral grain or a combination of
the two.
Curly‑Grained Wood—Wood in which the fibers are dis‑
torted so that they have a curled appearance, as in “birds‑
eye” wood. The areas showing curly grain may vary up to
several inches in diameter.
Diagonal‑Grained Wood—Wood in which the annual
rings are at an angle with the axis of a piece as a result of
sawing at an angle with the bark of the tree or log. A form
of cross‑grain.
Edge‑Grained Lumber—Lumber that has been sawed
so that the wide surfaces extend approximately at right
angles to the annual growth rings. Lumber is considered
edge grained when the rings form an angle of 45° to 90°
with the wide surface of the piece.
End‑Grained Wood—The grain as seen on a cut made
at a right angle to the direction of the fibers (such as on a
cross section of a tree).
Fiddleback‑Grained Wood—Figure produced by a
type of fine wavy grain found, for example, in species of
maple; such wood being traditionally used for the backs
of violins.
Flat‑Grained (Flat‑Sawn) Lumber—Lumber that has
been sawn parallel to the pith and approximately tangentG–6
General Technical Report FPL–GTR– 190