Building with Earth: Design and Technology of a Sustainable Architecture

(Nancy Kaufman) #1
Repair of damaged sections of loam, espe-
cially cracks and larger joints, demands spe-
cial measures differing from those used for
conventional masonry or lime plasters. This
chapter describes loam-specific repair prob-
lems and retrofitted thermal insulation
methods using lightweight loam.

The occurrence of damage in loam components


components

Damage in loam components can occur
due to shrinkage by thermal contraction and
expansion, through water impact or by
mechanical impact and abrasion.
If a plaster contracts when drying, or does
not bond sufficiently with the ground sur-

face, it may separate from it. Such weak
areas can be easily located by knocking the
plaster with the knuckles. If large quantity of
water condenses in the wall and cannot be
removed quickly enough, the loam might
swell and cause the plaster to crumble and
fall off. Such damage can also occur when
water seeps through from the outside
through cracks or holes.
Frost can also cause a similar damage if
the wall is moist and the freezing water
expands.

Repair of cracks and joints with other fillers


fillers

Joints and cracks in dry loam components
cannot be repaired with plastic loam as this
does not bond with the dry loam surface.
When drying, the filler will separate out and
can fall off. Therefore, it is important to pre-
treat the joint and use a mixture having as
little shrinkage as possible.

Mixtures
While designing the composition of the
loam filler for cracks and joints, the following
should be considered:


  • The filler must have sufficient binding
    force to stick to the moistened surfaces of
    the crack or joint.

  • The mix should contain sufficient coarse
    sand or other coarse particles so as to
    minimise the shrinkage. Fibres or hair may
    also be added for the same reason.


104 Repair of loam components

13 Repair of loam components


13 .1
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