For many mason contractors, cleaning questions repeatedly arise on the jobsite. From proper technique to environmental factors and material concerns, multiple factors must be considered when you prepare to clean a masonry structure.
To get answers to common masonry cleaning questions, MASONRY sat down with Marty Harris, Vice President of waterproofing, chemical and restoration products for Hohmann & Barnard/Diedrich. A former mason contractor, Harris worked for his family’s third-generation masonry company for 30 years. Today he puts that hands-on experience to work, overseeing product lines for H&B to include Diedrich masonry cleaning products.
Harris gives the following advice to masons for the cleaning and maintenance of masonry projects.
Masonry Magazine: How do I wash efflorescence and keep it from coming back?
Marty Harris: It’s important to understand what causes efflorescence in the first place. Understanding its causes allows us to find the proper steps to prevent or minimize efflorescence at the beginning stages of construction. Then, we can determine how to go about the cleaning process if or when it appears on new or existing masonry substrate – and keep it from coming back.
Efflorescence is salt deposits found in stone, brick, CMU, stucco and concrete when water is present in these materials. As the materials dry outwardly, salt is brought to the surface, causing efflorescence. The efflorescence appears as a powdery substance and requires special procedures to treat it.
Cleaning procedures for new masonry:
You can minimize the chance of having efflorescence by protecting products from moisture prior to installation, and by covering tops of unfinished walls. Efflorescence will most generally go away after an initial wash down, as long as water is not driven back into the material via water pressure that is too high during the washing process. Drying time is the best cure for efflorescence, but due to fast-paced construction schedules, time is of the essence.
When spot washing efflorescence, assure you don’t create a bigger problem by introducing more water to an issue already created by moisture. A few products in the market manufactured by reputable cleaning manufactures work well for cleaning efflorescence, after the initial wash is done. One product that I found is Spray-Away efflorescence cleaner, which can simply be sprayed on any leftover efflorescence. The job is done without scrubbing or rinsing.
Cleaning procedures for existing masonry:
Evaluate what is actually causing the efflorescence, so it doesn’t continue to return. Remember, efflorescence is caused from moisture and can happen in several ways. Improper wall ventilation, no weep vents, flashing issues, parapet caps, cracks in the mortar joints, walls exposed to the elements with no sealer, etc. can cause problems. Fix the problem, and then contact a reputable chemical manufacturer for cleaning instructions for various wall types.