Building with Earth: Design and Technology of a Sustainable Architecture

The stranglehmtechnique

At the Building Research Laboratory (BRL)

a new wet loam technique, termed the

stranglehm(“loam strand”) technique, was

developed in 1982. Walls, vaults and domes

can be built with this technique. Even built-

in furniture and sanitary items, as described

in chapter 14, p. 133, can be formed.

Production of stranglehmelements

In order to produce wet loam profiles, an

extrusion apparatus was developed by the

BRL. Using this machine, wet loam profiles

8 x 16 cm in section can be produced at a

rate of 2 m per minute (1.4 m^3 /h). This

prototype, which was arranged vertically,

as seen in 8 .15, was later refined, yielding an

output of 3 m per minute (2 m^3 /hr) using a

horizontal arrangement, as seen in 8 .16.

The machine consists of a feeder section

with two counter-rotating cylinders, which

mix the material before conveying it to a

section with rotating knives for mixing. The

material is then moved into a worm gear,

which creates sufficient pressure to force the

material out of the extrusion mouthpiece.

75 Direct forming

8.8Multi-storeyed
houses made using
the zaburtechnique,
Yemen
8.9 to 8.10Construc-
tion of a loam wall,
using the zaburtech-
nique
8 .11Traditional
Wellerbautechnique,
Germany
8 .12Cob building
from 1410, Cocking-
ton, Devon, England
8 .13Unplastered wall
of a sheep shed,
Dünne, Germany
8 .14Residence,
Dünne, Germany

8 .12

8 .13 8 .14