There are so many methods that can be used to clean dirty surfaces and chemicals to help you do the job. Ironically, one of the best ways to remove heavy dirt, oil, stains, mold, and mildew, and other contaminants is without chemicals and only using water pressure. The amount of pressure to be used on a particular cleaning job depends on the specific surface to be cleaned. The dusty exterior of a daily-driven vehicle can be rinse of with the pressure from even a garden hose up to the pressure of that of an automatic car wash. However, the pressure that can be used to clean a dirty driveway can be much greater as it is not as sensitive of a material and surface.
Most homeowners may use a consumer-grade electric pressure washer to wash their cars, decks, patios, garages, etc. and for most cases, that allows a homeowner to maintain their home and carry out small cleaning jobs in a relatively short amount of time. For larger cleaning jobs such as large patios, pool areas, and long driveways a consumer-level pressure washer may not provide ideal pressure and will also require significant time to clean as they typically have much lower gallon-per-minute ratings usually in the 2.5gpm range.
For heavy oil and caked on dirt, some commercial pressure washers utilize hot water to dissolve dirt and oil and can be used for cleaning heavy equipment such as trucks and tractors that accumulate caked-on heavy dirt and soil over time.
Although many customers are very familiar with the term “pressure washing“, not all surfaces should be pressure cleaned with pressure even though they may turn out to look better than not having cleaned at all. Not all surfaces are designed to withstand high pressures and some materials that may be weakened over time due to the weather are more likely to break or become damaged if pressure is used such as wood and vinyl siding. Also, in some cases, high pressure can even remove paint from materials. The main materials and surfaces that can handle high pressure cleaning are concrete driveways and brick pavers areas.
While water pressure can be used to cleaned hard surfaces like concrete, even high pressure can damage concrete surfaces if one is not mindful. Pool areas with concrete can be cleaned but some pool areas contain a softer concrete surface that should be taken into consideration as they can be cleaned with pressure but the pressure in pounds-per-square-inch (psi) should be reduced prior before cleaning. While some companies do pressure wash roofs, roofing shingles and other roof surfaces such as tile should not be cleaned using high pressure. Pressure removes the granules from the shingles reducing the quality and life of your roof. High pressure can also split and break tiles on the roof that are not only costly to fix but also may lead to leaks into your home.
In exterior house washing, the best method to utilize is called soft washing. Soft-washing utilizes chemicals and light pressure to apply these chemicals to the home without the possibility of forcing water into areas, lifting vinyl siding or destroying wood surfaces. The dirt and stains that are visible on a roof and on exterior walls of a home are mostly from mold and mildew and should be chemically treated to kill the mold and organic material instead of removal by physically means. It is worth mentioning that when dealing with organic material such as mold, it needs to be killed at the source as it is capable of attaching itself deep into the porous surfaces of concrete and wood and so simply utilizing water pressure does not adequately remove all of the organic material. This leads to your home simply not looking as clean as it could and also may result in the mold coming back much more quickly.