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Efflorescence Removal

Efflorescence RemovalEfflorescence occurs with all concrete and is the most frequent problem contractors face with coloured concrete, it is a crystalline deposit on the surfaces of masonry that the appearance of can detract from an otherwise beautiful structure or façade.

Efflorescence is caused when soluble salts and other water dispersible materials come to the surface of concrete and mortars. It's induced by low temperatures, moist conditions, condensation, rain, dew, and water added to the surface of fresh concrete to assist troweling. It can occur very soon after exposure to moist or cool conditions or gradually, especially when it comes from within the concrete or from the subgrade.

The easiest time to remove calcium hydroxide efflorescence is before it combines with carbon dioxide. Up to this time it will dissolve in water, so pressure washing or wet scrubbing will put it in solution with water so it can be rinsed away. You must be careful to rinse the surface with fresh water so that no residue is left to dry on the brick or stone work. Once past this early stage the best method is specific acid cleaning, this would be undertaken by our highly trained operatives to ensure the safe use and handling of such products. Failure to apply correctly can result in a ‘burning’ or discolouration to brick and stone.

Really stubborn problems can be dealt with by using our light sandblasting techniques; this requirement is normally after long periods of time without treatment.

What about sealants? Customer requirements vary once we explain how some sealants create a film to prevent or delay any further formation on the surface but may create a gloss effect to the surface, while an alternative is a penetrative sealant which soaks deeper into the surface to prevent or delay formation. Depending on the severity of the efflorescence it may be an option to leave the treated area an amount of time to exhaust itself of the combining properties and then apply the sealant rather than trap in the problem that may need further treatment later down the timeline. Our on- site surveys will determine which would be the most effective option for a specific case.