Environmental Engineering Reference
In-Depth Information
But who is now thatching roofs in Europe or North America, who is wearing straw
coats to protect against rain or weaving
waraji
(straw sandals) in Japan? True, Japa-
nese still produce
tatami
, woven rice straw mats whose dimensions (variable, but
mostly between 85 and 95 cm
180-190 cm) used to dei ne the size of rooms—but
that is a clear exception: in afl uent countries crop residues are no longer used either
in construction or in manufacturing. Wood is a different matter.
Many of wood's past (and until fairly recently large-scale) uses have also disap-
peared (nobody is building massive wooden ships, still dominant in the mid-
nineteenth century) and others have been reduced (new wooden bridges are relatively
uncommon)—but wood continues to have many obvious, universal, and lasting uses
(USDA 2010). Most people would list sawn wood (timber) as the principal structural
component; more i nely cut, trimmed, veneered, often bent and treated wood is used
for furniture; simply shaped wood is found in hand tools and gadgets ranging from
kitchen utensils (mallets, pins, skewers) to garden implements (stakes, rakes, trel-
lises); and pulped wood makes paper. But most people would not think immediately
of an enormous variety of past wooden uses, including weapons, tools, and farming
implements (spinning wheels, looms, rakes, l ails) and pipes.
And even some of today's less obvious but still very common wood uses might
escape those lists. Concrete and steel are now the dominant structural materials in
construction and tubular steel is the preferred material for scaffolding, but wood is
still used for concrete-forming molds, and in large parts of Asia bamboo scaffolds
still dominate. Worldwide, most railroad ties are still wooden, as are the under-
ground mine props or crates used to package heavy machinery. Other persistent uses
include the i nishing components of houses (stairs, doors, door and window frames,
l oors), barrels and casks for wine and spirits, specialty woods for musical instru-
ments and for sport implements, and many applications of plywood (layered wood
veneers whose commercial use began during the 1850s).
Even the afl uent countries do not have any disaggregated statistics for key wood
consumption categories before the late nineteenth century (at best there are estimates
of aggregate timber use for some earlier dates), and even basic order-of-magnitude
approximations of aggregate wood consumption are very difi cult to construct
because of an enormous variety of uses. Buildings have ranged from l imsy shacks
to massive log structures, vessels from small river boats with displacement of a small
fraction of 1 t to large naval sailing ships whose construction required several thou-
sand tons of sawn timber; and life spans of wooden structures extend from years
to centuries, or even to more than thousand years: wood for Japan's H ¯ry ¯ji pagoda
in Nara was cut 1,400 years ago.
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