【国外标准】 Standard Practice for Preparatory Surface Cleaning for Clay Brick Masonry

4.1 Surface cleaning is necessary to prepare clay brick masonry surfaces for application of coatings intended for water repellent protection. Surface cleaning helps to ensure proper adhesion or even penetration of the coating and to prevent unintended sealing-in of stains.4.2 This practice addresses surface cleaning only. Other preparation or remedial repairs, such as repointing the masonry or replacing of units, may be necessary and must be completed prior to application of the water repellent treatment.1.1 This practice covers non-abrasive surface cleaning of clay brick masonry to remove surface contaminants such as dirt, grease, loose material, soot, fly ash, hydrocarbon residues, algae, etc. in preparation for the application of water repellent coatings without damaging or altering the surface appearance of the clay brick masonry.1.2 Procedures included in this practice are water cleaning, detergent water cleaning, pressurized water cleaning, steam cleaning, and acid cleaning. It is not intended for the cleaning of newly constructed brick masonry. Use of procedures described in this practice may not be appropriate where the surface is of a historical nature.1.3 The values stated in inch-pound 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use. For specific hazard information see Section 5, 6.4.1.1, and 6.4.1.2.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.