Pressure Cleaning Methods
There is more to pressure washing than meets the eye. Proper equipment and use of that equipment in combination with the correct cleaning compounds is the key to a property being washed properly. Pressure washing equipment has PSI ratings (pounds per square inch) of up to and over 4000 PSI. PSI is basically the pressure or force that water comes out of a pressure washing gun and tip. On many surfaces such as concrete sidewalks, parking garage decks and patios, higher PSI is needed and safe when used properly. Unfortunately many consumers and some contractors are not aware that HIGH PRESSURE should NEVER be used when cleaning a home or a complex of buildings. 4000 pounds of pressure will damage most exterior building surfaces. Pressure washing equipment also has volume ratings expressed in GPM (gallons per minute). This volume helps in the cleaning and generally the more gallons per minute the quicker and more effective the cleaning process becomes. The GPM also helps in the rinsing process of washing. Usual GPM for building washing is in the range of 5-8 GPM. The higher GPM helps rinse more than the pressure. Lower GPM ratings take longer and quite often more pressure is needed to rinse. But once again HIGH PRESSURE and misuse of equipment can cause damage.
All equipment is not created equal. Obviously, equipment is an important component of any cleaning task. Machines differ, soap dispensers and applicators differ plus there are hundreds of different cleaning tips to use for application. Tip size helps control pressure, with the change of a tip you can go from 4000 PSI pressure down to a much lower and safer pressure. The average consumer would not easily recognize or appreciate the
difference in the equipment options and application. The professional contract cleaner understands the component of what is termed in the industry as a “cleaning unit” and what their specific equipment is capable of delivering. Professional pressure washing companies have an assortment of choices available to properly accomplish the different
projects in the course of their daily routines.
A low pressure wash with environmentally safe cleaning chemicals should be used on all exteriors when possible. Control of water pressure on the property project is a must. Professionals know one of the most important factors in cleaning is using correct detergent mixes. The chemicals clean, not pressure. The proper cleaning compounds are a key to excellent results. The professional uses the right detergent for the specific cleaning task. Stucco isn’t washed the same as vinyl siding. Painted wood isn’t washed the same as brick. In addition to correct detergent selection, using them at effective but safe concentrations to provide excellent results is a must. The professional also has the knowledge and training to know heat and cold effects, how well detergents work and will adjust concentrations based on ambient temperature. Appropriately adjusting detergent concentrations will provide excellent results in any climate. Water alone cleans very little. The proper selection and use of detergents make all the difference when cleaning all surfaces. No one cleaning chemical can clean all surfaces. Generally it’s a mix of chemicals that do the job properly, depending on the surfaces to be cleaned and what needs to be cleaned off of the surfaces. From a mild soap or detergent to more aggressive butyl based cleaners, there are a wide variety of good cleaners for the professional to use.
Mildicides such as bleach products to kill mold & mildew. In proper concentrations bleach products are completely safe and are needed in the south where we find more than our fair share of mold & mildew. There are also specialty cleaners that are often needed. Iron rust stains on buildings, concrete and other surfaces can easily be removed with the proper acidic cleaners. Cleaners to remove black streaks from gutters can be brushed on to make gutters look new. Aggressive commercial grade degreasers are available for removing oil & grease from parking garage decks. Paint and stain strippers and wood brighteners are available for decks, fences and docks. The professional pressure washing contractor researches and uses these cleaning compounds regularly. All of these cleaners come with MSDS sheets (Material Safety Data Sheets) and should always be available so the contractor and the customer may reference them as needed. MSDS sheets list the active ingredients, health & safety precautions and contact numbers in case of emergency or questions about the products.
Source: http://pressurewashingnews.com/
