Building with earth - Gernot MINKE (1)

7 Large blocks and prefabricated panels
7.1 Making lightweight
straw loam
blocks
7. 2 Exterior wall
made of large blocks
of lightweight straw
loam
7.1
With monolithic rammed earth walls, or
even with small-sized brick masonry, manpower
is high and drying time can delay
construction work due to the inherent
water. Therefore, several ideas involving
larger prefabricated elements have been
developed.
flipped over into their final positions (see 7.1
and 7.2). Using such blocks, a 50-cm-thick
wall gives a U-value of 0.3 W/m 2 K. Dufter
guided several do-it-yourself projects using
these blocks. In one case, the owner-builder
family produced 1500 blocks in five weeks,
sufficient for their entire house.
Lightweight mineral loam blocks measuring
15 x 15 x 30 cm, which are made of loam
and expanded clay, have been produced
in Hungary utilising egg layers (of the type
used in making concrete blocks) (7.3). Such
blocks were used to provide additional
external thermal insulation to a rammed
earth wall house in Tata, Hungary (7.4).
Different sections for larger wall panels
made of lightweight mineral loam, and
developed by the author of this book, are
shown in 7. 5. These can be used either in
Large blocks
69
Provided they are light enough to be carried
in one hand, or at most in both, larger blocks
can be laid faster. Lightweight aggregates
and cavities can be used to reduce weight.
For easy handling, grip holds should be
incorporated in block shapes.
Lightweight straw blocks, 50 x 60 x 30 cm,
used in several projects by the German
architect Sylvester Dufter, are more efficient
for making walls.Though each block weighs
26 kg, they are produced under cover and
close to the wall, and can then be almost
Larger blocks
7. 2