Building with Earth: Design and Technology of a Sustainable Architecture

Roof rafters should not rest directly on the
earth wall, but instead on timber wall plates
or beams as seen in 14.2 A. If the rafters
rest on a timber post-and-beam structure
and the wall is not load-bearing, the shrink-
age of the timber structure has to be taken
into account.
In 14.2 B, an elastic sealant has been intro-
duced between the beam and wall in order
to provide sufficient tolerance for this shrink-
age; while in 14.2 C, the structural system is
separated from the wall, thereby allowing a
greater vertical movement of the timber
structure.

Particular wall designs

Textile walls with loam infill

The U-value of a 30-cm-thick rammed earth

wall (without lightweight aggregates) is

about 1.3 W/m^2 K. In order to achieve a

U-value of 0.3 W/m^2 K with this wall, it

would need to be 1.65 m thick. This shows

that in cold climates where high thermal

insulation is required, it is not possible to

build only with normal loam.

The examples provided in 14. 3not only

show sufficient thermal insulation with a

U-value of 0.3 W/m^2 K, but are also designed

to have sufficient thermal mass for balanc-

108 Designs of building elements

14. 2Vertical sections

of roof structure and

load-bearing and

non-load bearing

walls

14. 3Horizontal sec-

tions of various loam

walls with U-values

of 0.3 W/m^2 K

14.4 Wall of discard-

ed car tyres filled with

soil, USA

14. 5Dome of earth-

filled hoses, Kassel,

Germany

14.6 Prototype build-

ing, Kassel, Germany

A B C

Timber boards

Windshelter

Thermal insulation (
= 0.04)

Earth blocks between

timber skeleton

Thermal insulation (
= 0.04)

Mineral lightweight loam between

timber skeleton (
= 0.21)

Thermal insulation (
= 0.04)

Load-bearing earth blocks

(
= 0.7) (
= 0.9)

Lime plaster

Cork (
= 0.5) Thermal insul. (
= 0.04)

Mineral lightweight loam (
= 0.21)

Lime plaster

Mineral lightweight loam (
= 0.18)

Timber skeleton

Lightweight loam plaster

14. 2

14. 3