Structural materials - The Ecology of Building Materials - page 237

Peat walls

Structural walls of peat were once
more widespread in Ireland, Scotland
and Wales. There are still a few peat
houses in Iceland, and this building
technique spread to Greenland dur-
ing the eleventh century. Building in
peat was also undertaken by immi-
grants in North America, especially
amongst the Mormons, who worked
a great deal with this material after
1850.
Peat is no easy material to build
with, and most of the alternative
building materials such as timber,
stone, concrete and earth are more durable and stable, but the question of econ-
omy and access to resources is also important.
A well-built peat house can have a life span of approximately 50 years, when
the decomposition of peat will be beyond its critical point. Peat has a higher
strength in a colder climate and with special climatic conditions such as those on
Iceland, and good maintenance, some examples have had a much longer life
span. One advantage of peat is its high thermal insulation. Icelanders worked
with two qualities of peat which they call strengur and knaus .

Figure 13.46: A traditional Icelandic dwelling made of peat.

Strengur is the top 5 cm of the grass peat and is considered the best part. It is cut into large
pieces that are laid in courses on the foundation walls. This method is particularly suitable for
dwellings. Knaus is of a lower quality. These are smaller pieces of peat, 12.5 cm thick, which
are laid according to the 'Klömbruknaus'
method (see Figure 13.47).
A serious problem with peat walls is
the danger of them 'slipping out'. This risk
can be reduced by stiffening the corners
with stone or short timber dowels which
can be knocked through the layers as the
building progresses.

The energy and material
used by different
structural systems

Figure 13.47: A peat wall contains layers of peat with earth
between them. In the corners, strengur peat is used; the rest of
the wall is laid with knaus . Souce: Bruun 1907

Every structural system has its own
specific use of material, depending