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Stone
is the oldest
construction
material
known to
mankind. The
most ancient
remaining
drystone
structures
are scattered
throughout
the world,
with Egyptian
pyramids
and Peruvian
temples as
world-class
examples. Prehistoric
dwellings
- brochs,
bories, trullis,
cabanes,
cleits, and
giren - extend
from the
Shetland
Islands to
the eastern
Mediterranean. Drystone
terraces
and canals
built to
aid agriculture
around the
world are
equally ancient
and widespread.
Since
colonial times, the United
States has built upon a rich
drystone heritage. Agriculture,
industry, and roadways developed
over 200 years using native
stone on a vast scale. On
farms, there were drystone
dwelling houses, barns, slave
quarters, spring houses, smoke
houses, and ice houses. Towns
contained stone court houses,
clerk’s offices, banks,
shops, inns, and churches. Structures
for transportation and early
industry include drystone mills,
dams, bridges, stream and pond
borders, iron furnaces, lime
kilns, and distilleries. Many
unnoticed drystone structures
still support daily use: retaining
walls at stream banks and road
cuts, railway piers and embankments,
and bridge piers and abutments.
Today, the most widely-recognized
historic drystone structures
are the stone walls and rock
fences that border fields,
pastures, and roadways in regions
of the country where building
stone was readily available.
Dry
stone has been a successful
building technique throughout
the ages because of its unique
range of benefits. It
provides good employment for
craftsmen without working capital
for heavy equipment. Masons
need a minimum of tools to
erect structures that are remarkably
durable; yet, if damaged, are
easily repaired. They
resist fire, water, and insects. If
correctly designed, they are
earthquake resistant. The
work does not deplete natural
resources, and aesthetically
compliments and enhances the
landscape.
Dry
stone structures have many
advantages over mortared
walls. Walls without
mortar rely on the skill of
the craftsmen and the forces
of gravity and frictional resistance. They
have a slight flexibility that
allows them to conform to foundation
settlement without damage. Because
the sides slope slightly inward,
ground movement locks the structure
more tightly together. Importantly,
a stiff concrete footing is
not needed, saving labor and
material expense.
Mortared
walls have a shorter life
span than drystone walls
because frozen rain and snow
get trapped in mortared
seams and push the joints apart,
whereas a correctly-built drystone
wall drains naturally without
damage. Accidents to
mortared walls tend to break
out large sections, making
damage-repairs costly. Mortared
walls also cost more to repair
because mortared rock is not
easily recyclable, requiring
additional new material.
Lack
of information and expertise
cause many architects, engineers,
and builders to depend on finite
answers to their building needs. It
is a goal of the Dry Stone
Conservancy to re-establish
the preeminence of dry stone
as a viable, preferred construction
method.
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