Wood Handbook, Wood as an Engineering Material

wood. The wood is generally straight grained and compara-

tively uniform in texture. Slow-grown wood is moderately

light in weight and moderately low in bending strength,

moderately soft, and moderately low in shock resistance.

The wood has moderately high shrinkage when dried from

a green condition, but it is not difficult to dry and is stable

after drying.

The lumber is used primarily for furniture, interior mould-

ing, siding, cabinets, musical instruments, and engineered

wood composites. Boxes, pallets, and crates are made from

lower-grade stock. Yellow-poplar is also made into ply-

wood for paneling, furniture, piano cases, and various other

special products.

U.S. Softwoods

Baldcypress

Baldcypress or cypress

(Taxodium distichum) is

also known as southern-

cypress, red-cypress,

yellow-cypress, and

white-cypress. Commer-

cially, the terms tidewater

red-cypress, gulf-

cypress, red-cypress

(coast type), and yellow-cypress (inland type) are fre-

quently used. About half of the cypress lumber comes from

the Southern States and about a fourth from the South At-

lantic States. Old-growth baldcypress is difficult to find, but

second-growth wood is available.

Sapwood of baldcypress is narrow and nearly white. The

color of heartwood varies widely, ranging from light yel-

lowish brown to dark brownish red, brown, or chocolate.

The wood is moderately heavy, moderately strong, and

moderately hard. The heartwood of old-growth baldcy-

press is one of the most decay resistant of U.S. species, but

second-growth wood is only moderately resistant to decay.

Shrinkage is moderately low but somewhat higher than

that of the cedars and lower than that of Southern Pine. The

wood of certain baldcypress trees frequently contains pock-

ets or localized areas that have been attacked by a fungus.

Such wood is known as pecky cypress. The decay caused

by this fungus is stopped when the wood is cut into lumber

and dried. Pecky cypress is therefore durable and useful

where water tightness is unnecessary, appearance is not

important, or a novel effect is desired.

When old-growth wood was available, baldcypress was

used principally for building construction, especially where

resistance to decay was required. It was also used for

caskets, sashes, doors, blinds, tanks, vats, ship and boat

building, and cooling towers. Second-growth wood is used

for siding and millwork, including interior woodwork and

paneling. Pecky cypress is used for paneling in restaurants,

stores, and other buildings.

Douglas-Fir

Douglas-fir (Pseu‑

dotsuga menziesii) is

also known locally as

red-fir, Douglas-spruce,

and yellow-fir. Its range

extends from the Rocky

Mountains to the Pacific

Coast and from Mexico

to central British

Columbia.

Sapwood of Douglas-fir is narrow in old-growth trees but

may be as much as 7 cm (3 in.) wide in second-growth

trees of commercial size. Young trees of moderate to rapid

growth have reddish heartwood and are called red-fir. Very

narrow-ringed heartwood of old-growth trees may be yel-

lowish brown and is known on the market as yellow-fir. The

wood of Douglas-fir varies widely in weight and strength.

Douglas-fir is used mostly for building and construction

purposes in the form of lumber, marine fendering, piles,

plywood, and engineered wood composites. Considerable

quantities are used for railroad crossties, cooperage stock,

mine timbers, poles, and fencing. Douglas-fir lumber is

used in the manufacture of sashes, doors, laminated beams,

general millwork, railroad-car construction, boxes, pallets,

and crates. Small amounts are used for flooring, furniture,

ship and boat construction, and tanks.

Fir, True (Eastern Species)

Balsam fir (Abies bal‑

samea) grows principally

in New England, New

York, Pennsylvania, and

the Great Lake States.

Fraser fir (A. fraseri)

grows in the Appalachian

Mountains of Virginia,

North Carolina, and

Tennessee.

The wood of the eastern true firs is creamy white to pale

brown. The heartwood and sapwood are generally indis-

tinguishable. The similarity of wood structure in the true

firs makes it impossible to distinguish the species by ex-

amination of the wood alone. Balsam and Fraser firs are

lightweight, have low bending and compressive strength,

are moderately low in stiffness, are soft, and have low resis-

tance to shock.

The eastern firs are used mainly for pulpwood, although

some lumber is produced for structural products, especially

in New England and the Great Lake States.

Chapter 2 Characteristics and Availability of Commercially Important Woods