There certainly is a lot of misconception involved when it comes to using a pressure washer to clean various surfaces. Most pressure washers, even small consumer grade ones, will put out at least 2000 to 2500 PSI or more. That is plenty of pressure to easily damage the surfaces around your home such as vinyl siding, shingles, wood and even certain types of brick and concrete.
The misconception with pressure washers is that most people think the pressure does all the work; after all it is called a pressure washer. But honestly nothing could be further from the truth. Even small power washers should have the pressure backed down before washing most surfaces. The problem is the nozzles that come with a new pressure washer allow for the maximum amount of pressure. This is like buying a new car and driving it around with the gas pedal smashed all the way to the floor which would definitely be reckless and probably would cause some serious damage. It is necessary to buy different nozzles that allow for the use of lower pressures without sacrificing the flow or the gallons per minute.
Too many people, including inexperienced contractors, rely too heavily on the pressure to do the cleaning.  Two major problems are caused by this; the first is what was mentioned earlier, the risk of damage to your home’s vinyl, deck, roof, window screens and so on. The second problem is because they are relying on pressure they are not using very effective cleaners if any. Due to this, contaminants like mold, mildew and algae are just blasted off but not killed resulting in them returning in a few short months. It is necessary to use the proper cleaners so these contaminants are killed and so low pressure methods can be used eliminating risk of damage. Be sure the pressure washing company you hire use the low pressure methods.

Many home improvement projects around your home and property can be accomplished with a pressure washer. The proper way to tackle these projects, whether you are going to hire or do it yourself, is to become educated by researching. For instance, using the proper cleaners so that excessive high pressure is not needed is something important to know to help eliminate the risk of damage to your property. Too much pressure can easily damage wood, vinyl siding, asphalt shingles and brick mortar as well as other surfaces. When using a contractor grade house or deck wash you can use less pressure, eradicating the risk of damage, yet still achieve terrific results.
The way the pressure is lowered on a power washer is by changing the nozzle at the end of the wand. Usually the nozzles that come with pressure washers are designed to allow for the maximum amount of pressure in various fan degrees. It will probably be necessary to obtain different nozzles from a pressure washer dealer to achieve a lower pressure.
You should also educate yourself on the safe handling of the chemicals involved, proper equipment and washing methods. If you plan on hiring be sure to ask the contractor what their methods and cleaners are so you know what to expect. Be sure they are going to use contractor grade cleaners, equipment and low pressure methods.