Building with Earth: Design and Technology of a Sustainable Architecture

84 Tamped lightweight loam

than 25 cm in thickness, the straw might rot
in the interior of the wall. Illustration 10. 4
shows an example of a 30-cm-thick wall
built of lightweight straw loam with a densi-
ty of 350 kg/m^3. After some months, when
the outside appeared to be completely dry,
the core was chased for an electrical instal-
lation, and was found to be rotting. Even
the structural timber member had been
attacked by micro-organisms to depths of
2 cm (Schmitt, 1993). With lightweight walls,
wood lice may also appear and eat the
straw. Therefore, it is always advisable that
the stacks of straw are totally sealed by the
loam, which means that the mixture should
have a density of more than 600 kg/m^3.

Tamped lightweight wood loam walls

Wood chips and sawdust are often used as
lightweight aggregates instead of straw.
These are easier to mix with the loam, but
have a lesser degree of thermal insulation
effect, and drying takes a very long time.
Illustration 10. 5shows the 50-cm-thick wall
of a restored historic building whose wood-

10. 3

10. 4 10. 5

10. 7