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Friday, 9 January 2009

Effects of efflorescence on Bricks?

Effects of Efflorescence on Bricks?
Efflorescence is that white powdery looking substance that appears on some brickwork This can be unsightly in new brickwork and some people try to take off the white deposit by applying more water to it in the hope that it will lessen its effects. Instead of getting rid of the efflorescence it actually makes it worse and the best way to get rid of it is with a scrubbing brush,no water, and good old fashion elbow grease.
How would efflorescence damage masonry?
Continual saturation with soluble salts, can cause deterioration of
masonry, if the materials are soft like stone, soft blocks, and non British Standard bricks
This continual wetting with ground water or water high in soluble salts can
make the materials susceptible to frost attack also the salt crystals can
build up inside the masonry expanding as the frost water molecules do,
destroying the face.
Water molecules expanding within the face of the masonry will make the
face breakaway and flake, leaving the masonry unsightly and over a long
time unstable.
Lime mortar will be affected, as the soluble salts will attack the lime the
chemical reaction between the soluble salt and the lime creating sulphates
that weakening the mortar.
With face stone work particularly stone containing limestone, the soluble
salts will cause a chemical reaction between the soluble salt and the lime
creating sulphates, leaving the masonry susceptible to atmospheric attack
from acid rain and frost etc

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