Building with earth - Gernot MINKE (1)

resemble skyscrapers, and date from the
15th century (6.2).
In Scandinavia and in England, building with
sod was common in the 17th and 18th centuries.
These houses were constructed of
blocks cut from the top layer of loamy soil
together with the grass growing on it. The
blocks were inverted and used as bricks to
form walls without mortar. European immigrants
brought this technique to the USA,
where a large number of sod houses were
built in the 18th and 19th centuries (6.4).
Some settlers also adapted the same idea
from North American Indian nations such
as the Omaha and Pawnee, who for centuries
had used the method to cover their
round huts with sod (Houben, Guillaud,
1984).
In New Mexico, silty soil blocks cut from
riverbeds, and containing a network of roots
which act as reinforcement, were used
for building walls. These blocks are called
terronis or terrones, and were sometimes
used in Mexico and Central America as well.
It is interesting to note that building codes
in New Mexico still permit building with
terronis.
In Germany, earth block work was used
in the 6th century BC; adobe blocks
40 x 40 cm and 6 to 8 cm high were used
in the fort of Heuneburg near Lake Constance
(Dehn, 1957). Around 140,000 blocks
and 400 m 3 of mortar were used to construct
its 3-m-high walls (Güntzel, 1986,
p. 23). An official circular introducing the
use of adobes in walls was published in
6.4
62
6.6
1764 (Güntzel, 1986, p. 23). David Gilly published
manuals on adobe construction in
1787 and 1790.
Production of earth blocks
Adobes are made either by filling moulds
with a pasty loam mixture or by throwing
moist lumps of earth into them. Different
types of moulds can be used; some of
these are shown in 6.5. They are usually
made from timber. The throwing technique
is commonly used in all developing countries
(6.7, 6.8 and 6.9). Here, a sandy loam is
mixed with water, and cut straw is usually
added and the whole formed into a paste
that is thrown into wooden moulds. The
greater the force with which the loam is
thrown, the better its compaction and dry
strength. The surface is smoothed either by
hand or by a timber piece, trowel or wire
(6.6).
One person can produce about 300 blocks
per day (including preparation of mix, trans-
Working with earthen blocks
6.3 Traditional earth
dwellings of the
Pueblo Indians, Taos,
New Mexico, USA
6.4 Sod house, USA
6.5 Moulds for
adobes
6.6 Removal of surplus
loam with a wire
6.5
6.3