Masonry is usually cleaned with pure water and if necessary a device such as a brush. The use of acids is not approved.

Light spots, such as hardened mortar splatters, can be easily removed with a trowel. A final cleaning can also be done with a scouring pad or sandpaper (fine grain) or with a half or quarter SL block.

In case heavier cleaning is necessary, a thorough rinsing is recommended. This can be done with pure water and a brush – best done using netting so that the surface tension of the water can be broken. Steam-cleaning has also proven effective for larger areas. However steam pressure and the distance of the nozzle to the masonry must be tested on a sample section, so that the surface of the block is not affected too much and color differences can be avoided.

Acid washes are not approved for sand-lime masonry.