Remove large deposits with wooden implements to avoid damaging the paver surface. Following the pre-wetting of the area, treat the residue of mortar by careful application of a dilute hydrochloric acid solution or a proprietary cleaning solution. The application of the acid breaks down the cementitious components but is not damaging to clay pavers.
As with all cleaning procedures a rinsing operation should be carried out shortly after application, and care taken to dispose of run off solutions safely.
If the above method is not successful with coloured mortars, specialist advice from the coloured mortar supplier should be sought.
On the rare occasions when a vanadium efflorescence is present, hydrochloric acid based cleaners must not come into contact with the efflorescence, otherwise a dark stain will result which will become fixed on the surface.