Efflorescence is a technical term used to describe the unsightly fluffy salt crystals which can accumulate upon cement and plastered walls, lifting and splitting the paint. It usually occurs in patches on lower wall areas, corners and around windows and door recesses.
It is not uncommon for Efflorescence to appear on newly plastered walls, particularly if they had not fully out either before the application of paints or afterwards.
How to Rectify and Proceed
Efflorescence Removal Solutions are widely available, and should only be used after reading the manufactures instructions; however there is no reason to purchase these products as efflorescence is easily rectified.
Scrape off all the salt crystals and the loose and defective paintwork back to a firm edge. Lightly sand down the affected area and then wipe down with a diluted Sugar Soap solution or mild household detergent and allow to fully dry.
The treated area should be primed with either a mist coat of diluted emulsion or an Alkaline Resisting Primer depending on the decorative finish required. You may need to surface fill the repair to disguise any raised edge between the existing surface and the repair before applying the finishing paint.
If Efflorescence unexpectedly appears on much older walls there may be an issue such as a faulty damp-proof course, a weeping water pipe or some other cause of moisture accumulation triggering the efflorescence. Test with a moisture meter before proceeding with any corrective redecoration.