From NCMA eNews
July 18, 2019
Yes, there are in general three ways a masonry assemble can be cleaned; water cleaning, abrasive cleaning, and using some form of chemical. Water cleaning method is effective for simple stains resulting from dirt, mild efflorescence, grease stains etc. Water cleaning can be done with or without pressure washing tools and can be accompanied by other cleaning products such as a mild detergent and non-metal cleaning brush. Water cleaning is the quickest and simplest method of cleaning and in general is useful for mild stains resulting from dirt, grease, or mild efflorescence. For more information on ways to clean CMU assemblies, see TEK 8-2A Removal of Stains from Concrete Masonry.