For the professional property owner or manager, upkeep of a building's exterior envelope is a matter of key importance. A property's curb appeal can directly affect the rental occupancy rate, the saleability of the property, and the first impression potential customers have of your business. First impressions are most often lasting impressions. In keeping up a property's appearance, one aspect of maintenance that should not be overlooked is the benefit of periodic cleaning of exterior surfaces. A building that shows a dull layer of dirt and grime, mineral stains, and/or mold and mildew will look old beyond its years, no matter how well kept the property is in all other regards. All exterior building surfaces, including brick, stone, vinyl, wood, concrete, and EIFS, can be pressure washed. A competent cleaning professional will have the experience and skill to efficiently and effectively clean a variety of exterior materials without causing damage. The popular EIFS or Dryvit exteriors, for example, benefit from periodic pressure washing, but require care in cleaning because the synthetic stucco layer is soft and can be harmed by excessive water pressure. The EIFS surface texture is prone to collecting dirt, and in shaded areas to growing mold and mildew. If left to accumulate these contaminants not only become an increasing eye sore, but will begin to degrade the outer color coat. With professional washing techniques, EIFS exteriors can be safely cleaned and kept looking new indefinitely. Traditional brick or stone exteriors are particularly prone to mold and mildew growth, as well as environmental staining, efflorescence, and hard water staining. With the correct washing procedures, biological growth and years of accumulated surface stains can be safely removed to reveal the natural beauty of traditional brick and stone exteriors. Pressure Washing Basics To achieve the best results the professional will consider the characteristics of the surfaces being cleaned and the contaminants being removed and use a varying combination of water pressure (PSI), water flow (GPM), heat, and detergents. Some types of surface contaminants can be removed by water pressure alone, while heat and/or detergents may be needed to break down and wash away others. All cleaning projects require an understanding of the environmental affects of the proposed methods. An experienced cleaning contractor will advise what technique works best for any given situation, and have available the right equipment and personnel for the job. Unlimited Pressure Washing Applications Pressure washing applications abound for commercial properties. Many plaza owners and managers maintain the appearance of their properties through regularly scheduled cleaning of sidewalks, storefronts, canopies, and signage. Accumulated dirt, gum, soda, and cigarette stains are removed using very hot water, prudent amounts of pressure, and detergents only as necessary. Bus stops, trash barrel enclosures, sitting areas, and high pedestrian traffic areas all will benefit from regularly scheduled cleaning. Pressure washing of parking garages will greatly limit degradation from winter salt accumulation and help maintain the structural integrity of the concrete. Pressure washing of walkways can reduce liability exposures for the property owner. Walking surfaces in shaded areas and near landscaping will grow mold and mildew and become slippery. Likewise pavement surfaces near dumpsters at restaurant establishments will become slick from grease and fat drippings. Regular cleaning of such walking surfaces will reduce the potential for slip and fall claims. Selecting a Pressure Washing Contractor In recent years the pressure washing industry has caught the attention of the "start your own business" promoters and other companies attempting to provide pressure washing as an "add-on" service. As a result there are some marginal cleaning services in existence that have limited expertise and limited equipment. The danger of using the wrong cleaning contractor is that they may permanently damage the surfaces you are trying to clean. For that reason, careful screening is in order before hiring a pressure washing service. The contractor you select should be responsive and able to give knowledgeable answers to your technical questions. They should be willing to provide certificates of insurance to show that they are fully insured, and they should be able to provide customer references for the type of pressure washing service that you are seeking. Pressure washing is a key component of exterior building envelope maintenance. Regularly scheduled cleaning by a competent professional contractor will add value to your commercial property and keep it looking its best for years to come. David Friedman is the president of INSTA-BRITE Mobile Washing, Inc., Whitman, Mass.