Surface cleaning is necessary to prepare architectural sandstone surfaces for application of coatings intended for water repellent protection. Surface cleaning of the sandstone substrate helps to ensure proper adhesion of the coating.

Use of procedures described in this practice may not be adequate where protective systems will be used for continuous or intermittent immersion or mechanical loading.

1.1 This practice covers non-abrasive surface cleaning of architectural sandstone to remove grease, dirt, loose material, and surface deposits such as soot, fly ash, hydrocarbon residues, and algae and other biological growth in preparation for the application of water repellent coatings. Procedures include broom cleaning, vacuum cleaning, air blast cleaning, water cleaning (and detergent water cleaning), and chemical cleaning.

1.2 Limitations—This practice is intended to clean architectural sandstone without damaging it or altering the surface profile. These procedures are not intended for interior stonework. Where work on surfaces of artistic, architectural, cultural, or historic significance is being considered, guidance from specialists should be sought.

1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 4.