HomeownerEducational: N-Z

Pressure Washing

Pressure washing, or power washing, is a specialized home exterior cleaning service used to clean siding, windows, eaves, decks, patios, concrete, limestone, and other surfaces.

Mildew, algae, dirt, and particulates in the air can gradually dull your house, patio, and driveway (and plenty of other surfaces around your property). Stains and discoloration can be difficult to remove by hand, and a pressure washer can clean a greater area in a shorter period of time than a person can accomplish with a scrub brush and a bucket of soapy water.

A pressure washer can direct a jet of water exerting up to 3,000 pounds per square inch (psi) of pressure along surfaces at varying angles and spreads, but for most residential jobs, this level of power isn’t necessary. Low-pressure power washing, also called soft washing, is sufficient for the majority of residential exterior cleaning needs. Chemicals or solvents may be used to clean specific types of stains and certain surfaces.

Pressure Washing Equipment

Professional pressure washing companies have a range of specialty tools and cleaning solutions at their disposal, all designed to clean a variety of surfaces. High-quality equipment is important, but a knowledgeable pressure washing technician is key to a job well done. Your technician should have experience using a pressure washer on a variety of surfaces, including concrete, wood, masonry, vinyl, and composite.

Most professional pressure washing companies use gasoline-powered pressure washers. Electric pressure washers are available, but because gas-powered machines offer more power and more efficient cleaning, electric machines are not as popular with the pros.

Gasoline-powered pressure washers use a small engine to create power, so they require periodic maintenance and oil changes. These types of pressure washers are popular for cleaning large properties because they don’t need an electrical outlet.

Electric power washers, on the other hand, require less maintenance than their gas-powered counterparts, but they are less convenient for cleaning large surfaces, such as an entire driveway or a long expanse of wooden fencing.

The power of a pressure washer is measured in a couple of ways. Pounds per square inch (psi) is a measure of how much pressure the machine’s compressor can create. Gallons per minute (gpm) is a measure of how much water can flow through the pressure washer. When combined, these two measurements indicate the cleaning power and efficiency of the pressure washer.

While the psi and gpm ratings of a pressure washer are important, the operator’s nozzle choice is equally important. The nozzle size directly impacts the pressure of the water applied to a surface as well as the amount of cleaning solution required. Pressure washer nozzles are what determine the angle of the water sprayed by the machine’s wand (and thus, the force with which the water hits a surface).

Most pressure washer nozzles range in spray angles from zero degrees to 65 degrees. Zero-degree nozzles spray water with enough force to gouge surfaces and strip paint, so they should only be used by professionals when necessary. Pressure washer nozzles that spray water in wider angles are easier and safer to use around the house.

Adjustable nozzles and wands make cleaning tight or awkward spaces easier. Professional pressure washers know which nozzle to use on a given surface to efficiently remove dirt and grime while avoiding damage.

Depending on the surface to be cleaned, professional pressure washers may use a standard wand and nozzle combination, or they may use a specialized pressure washer attachment. Surface cleaners are unique attachments that allow the operator to clean large areas with more power and more efficiency than one wand alone.

Related Services

Many pressure washing companies also offer additional home exterior cleaning services such as gutter and window cleaning. A clean exterior makes a huge difference in your home’s curb appeal, so be sure to ask your pressure washing contractor about these extra services.

In most cases, professional pressure washing companies will use soft-washing techniques to clean windows, gutters, and some types of exterior cladding. A high-pressure stream of water can easily shatter a window or cause aging brick or masonry to disintegrate, but soft washing, when performed by an experienced power washing technician, can clean a wide variety of surfaces without damage.

If your home’s siding, exterior trim, deck, or other surface was painted prior to 1978 and is now peeling, it should not be pressure washed. Lead paint was banned in 1978, but paint that was used prior to the ban could contain lead. Power washing, even when it is performed at a low pressure, can release paint chips and dust into the environment. If those paint chips contain lead, they are poisonous and should not be breathed in or ingested by humans or animals.

Peeling lead paint can be removed by following specific safety and disposal procedures. If your pressure washing contractor is an EPA Lead-Safe Certified Firm, they are qualified to safely handle and remove lead paint.

Pressure Washing Companies

Most pressure washing companies offer their services year-round, barring severe weather. If you live in a part of the country that experiences very cold, snowy winters, however, try to schedule pressure washing services for the late spring or early summer. Most trees and flowers will have budded out by that time, so your pressure washing contractor will be able to remove stains from fallen leaves and flowers as well as salt and dirt residue from the winter’s precipitation.

Mildew thrives on concrete and home exteriors in warm, damp weather, so homes in humid climates will likely need to be pressure washed more often than those in dry climates. If you live in a coastal area, schedule an annual pressure washing service to remove salt deposits that can cause corrosion.

The average pressure washer sprays water with such force that it can do significant damage in the wrong hands. Pressure washing takes skill, experience, and knowledge of techniques and chemicals. It is not a job to DIY. Because of the potential for damage and injury, be sure that the pressure washing company you choose has plenty of experience and maintains all state-required general liability and worker’s compensation insurance policies.