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Efflorescence
"Efflorescence" is a crystalline
deposit of soluble salts on a surface that results from the
migration and evaporation of water. Efflorescence is a temporary
phenomenon and will weather away naturally.
In a building, the appearance of efflorescence
results from wet brickwork drying out and may be due to excessive
wetting during construction, or due to inadequate protection
and design detailing allowing water to percolate through parts
of the completed construction. In addition, soluble materials
from other sources, including the mortar, may contribute to
the amount of efflorescence observed in practice.
We recommend that design and workmanship be
in accordance with BS 5628-3 or I.S. 325 Part 2. This will
ensure that architectural detailing is in accordance with
recommended practice and that sound site practices are adopted.
Good design and workmanship will help avoid efflorescence.
Failure to provide adequate protection will almost certainly
lead to efflorescence with any fired-clay brick.
Bricks produced by Ormonde Brick Ltd. are of
"Slight" efflorescence category when tested in accordance
with I.S.91 / BS 3921. Our bricks are giving satisfactory
service in many hundreds of buildings throughout Ireland and
Great Britain for many years past.
Any efflorescence which occurs should be allowed
to weather away naturally. Efflorescence may be removed by
brushing with a stiff bristle brush. The deposit should be
collected and removed so that it does not enter the masonry
at lower levels. Any deposit remaining may be removed or reduced
by treatment with clean cold water. Since the deposit is water
soluble, washing down may result in the solution being partially
re-absorbed. This may be minimised by using a clean damp sponge,
which should be rinsed frequently in clean water. Chemical
methods should not be used for removal of efflorescence.
BS 8221-1 and BDA Building Note 2 give guidance
on the cleaning of clay brick masonry.
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