Repairs: walls

Effluorescence is one of the most common causes of staining to masonry. It generally affects new work rather than older buildings. The visible white staining occurs when the salts within the clay of the brick (or tiles) are dissolved by rainwater and washed to the surface, where they dry.

It may be unsightly but is not a significant problem, unless the deposits are at a low level on the elevation, in which case they suggest a failure of the DPC and/or rising ground water (a possible explanation for effluorescence in older buildings).

Solution 1

Increased hosing down and brushing may help accelerate the removal of the salts, but it can take years to eventually disappear.

Solution 2

If a DPC problem is identified, it will be necessary to break out the masonry course and sleeve-in a new DPC membrane.

Effluorescence – salts have crystallised on the wall in an underground tunnel, but the staining can take the form of white chalk-like deposits over the surface of the brick