Exterior house cleaning is the important first step of a quality paint job. Contaminants like dirt particles tend stick to exterior painted surfaces. Spider webs often accumulate on the underside of the eaves or soffits. Sun damaged paint can become chalky. Mold and mildew are quite common on painted surfaces with poor exposure to the sun. These are some examples of circumstances that, if not properly cleaned, can create adhesion problems for the new coats of paint.
Washing the exterior painted surfaces with water using a pressure washer or a garden hose and nozzle, will remove the majority of contaminants. Using a medium or stiff bristle scrub brush works well to loosen stubborn grime and remove chalky paint and stain. A scrub brush is a very effective tool for cleaning rough surfaces such as re-sawn wood, textured stucco, and brick. Try to obtain a scrub brush that can be attached to an extension pole. This will make the exterior house cleaning go much faster and easier.
Be aware that improper use of a pressure washer can do significant damage to the exterior of a home. This is especially true for wood surfaces. Use the spray tip with the widest spray fan for general cleaning purposes.
When cleaning areas that are not intended to be repainted, it is best to use a gentler method of scrubbing so as not to damage the existing paint. A soft sponge along with soapy water works well to clean painted doors, windows, trim, and gutters. Rinse away the soap residue with a garden hose and nozzle.
Removing mold and mildew requires more than just water cleaning. Cleaning products formulated to eradicate mold and mildew are usually available wherever you purchase your paint.
There are three types of deck cleaning products that are widely used. Deck cleaners are designed to remove dirt, decayed leaves, grease, mildew, and other foreign matter from stained and painted decks. Deck Strippers are effective at softening existing coats of stain so that they may be rinsed away with water. Deck Brightener is used to strip off sun damaged wood fiber and remove rust and tannin stains from stained decks.
Many of the leading paint manufacturers produce exterior house cleaning products formulated for painted and stained surfaces. Some of these cleaners contain caustic chemicals, so care should be taken when in use.
Non toxic alternatives, such as enzyme cleaners, are also very effective cleaners.
During the cleaning process, try to avoid spraying high pressure water directly onto windows and doors. This can cause leaks and damage interior surfaces. It is also a good idea to prevent excessive amount of water from seeping into attic vents. Finally be careful with exterior devices such as light fixtures, speakers, cameras, etc.
Houses built before the mid 1970s have a high probability of having been painted with lead based paints. Make sure to observe all applicable laws and regulations regarding lead based paints. For additional information, go to the EPA/lead paint.