Mighty Clean: Pressure Washing 101

Rejuvenate siding, decks, patios, driveways, fencing, outdoor furniture, lawn mowers, grills, and more with a healthy blast of H2O.
Mighty Clean: Pressure Washing 101
Pressure washing can instantly improve a house's appearance, making it look cleaner and better maintained. Alan Budman/Shutterstock
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Pressure washing and its big brother, power washing (aka hot pressure washing), can make a home look new in just a few hours. It’s necessary before painting a home, re-staining a deck, or even refinishing a pool.

In addition to being much faster than hand-scrubbing surfaces, pressure washing offers a deeper clean, particularly when it comes to nooks and crannies.

Did you know that mold actually feeds on paint and other coatings? Likewise, dirt and grime buildup can eventually turn into permanent damage, requiring a whole house repaint. When used properly, pressure washing will get the deepest crevices clean without causing any damage.

Light PSI

The cleaning process starts with either purchasing or renting the ideal PSI (pounds per square inch) machine for the surface(s) being cleaned.

Units start as small as 100 PSI to 750 PSI. These are normally battery-powered models that are designed for quick, portable spot cleaning or other small, light jobs that don’t require getting out the bigger machine. Some even have the option to draw water from a five-gallon bucket instead of dragging a long length of hose around. They excel at cleaning windows, spot cleaning lightly soiled patio furniture, including cushions, and rinsing off cars, RVs, motorcycles, bicycles, and scooters. At this size, they are normally available only for purchase rather than renting.

Remember that even with a low-PSI model, pressure washers are dangerous—never aim them at another person, even when just horsing around.

For all other jobs, a 1,000 PSI to 1,900 PSI light-duty washer is normally the bare minimum. Although there will be an overlap with the smaller guys when it comes to washing vehicles and cleaning outdoor furniture, the increased pressure makes the work quicker and it can remove tougher and more-ground-in stains. Designed for the light-use homeowner, they also make short work of cleaning small patios and decks and outdoor play equipment, whether plastic, metal, or wood.

Models offer different sizes, water temperatures, safety features, GPM, PSI, pump types, and more. (Mariana Serdynska/Shutterstock)
Models offer different sizes, water temperatures, safety features, GPM, PSI, pump types, and more. Mariana Serdynska/Shutterstock

Ramp Up the Power

Medium-duty pressure washers (2,000 PSI to 2,800 PSI) are for more-robust, protracted jobs, including comprehensive paint prep. They are ideal for cleaning home exteriors, washing really dirty cars, trucks, RVs, boats, or cleaning large patios and decks. They can also be used to strip paint from decks and, with care, can handle some more-delicate tasks such as cleaning outdoor furniture and play equipment that is otherwise in good condition (i.e., not falling apart and vulnerable to high-pressure spray).

One step up, heavy-duty pressure washers (2,900 PSI to 3,300 PSI) will quickly remove built-up dirt and grime from siding or stucco exterior walls, strip coatings and sealers from concrete and brick, and brighten up a dingy sidewalk. They’re the right choice for large driveways or even parking lots.

Many commercial pressure-cleaning businesses use this size machine, while truly professional-grade machines are considered to be 3,400 PSI and above. Those are used for restoring severely built-up dirt, grime, etc., on concrete and brick, cleaning multi-story buildings in preparation for paint or sealing, and removing graffiti.

While there is a temptation to think that bigger is better, selecting too high a PSI can damage the surface being cleaned, particularly wood surfaces such as siding and decks.

Pressure washing pathways effectively removes built-up dirt, debris, mold, algae, and stains from concrete, brick, stone, or asphalt surfaces. (Daria Nipot/Shutterstock)
Pressure washing pathways effectively removes built-up dirt, debris, mold, algae, and stains from concrete, brick, stone, or asphalt surfaces. Daria Nipot/Shutterstock

Heat Things Up

Although the terms “pressure” and “power” sometimes are used interchangeably, a genuine power washer heats up the water significantly to remove mold and mildew and to dissolve thick grease and hardened grime.
Be warned: Some professional models can achieve water temperatures of more than 200 degrees F and cost more than $1,000, although rentals are typically available. These are not something that a homeowner needs every day, and they definitely need to be used with caution, as they can damage soft materials such as wood. But, it’s good to know that they’re out there.

Additional Decisions

The power source is another consideration. Electric is highly suitable for home use when there is an outlet or extension cord nearby (use a 12- or 14-gauge cord no longer than 60 feet, and keep the plug away from any water at all times). Gas-powered machines typically offer higher PSI and are more portable, but may require winterization in cold climates.

Also check out the machine’s gallons per minute (GPM) rate. A higher GPM will get the job done faster. Common GPMs are 1.5 GM to 2.5 GM for light jobs, such as washing the car, and 2.4 GPM to 4 GPM for cleaning sidewalks and siding.

When in doubt, rent before buying. Or better yet, borrow a machine from a neighbor, being sure to return it with doughnuts.

All-Important Accessories

A soap attachment filled with specially formulated pressure-washer detergent leaves vehicles, outdoor furniture, and more sparkling clean. Also:

Take Aim

Add a nozzle set or adjustable nozzle to take advantage of a zero-degree pencil jet for concentrated, targeted cleaning, a 15-degree pencil jet for focused high-performance flow, a 25-degree pencil jet for multi-purpose use, a softer 40-degree nozzle for sensitive surfaces, and a 65-degree nozzle for soap/detergent application.

Brawny Brush

A wash brush with fixed exterior bristles and rotating interior bristles quickly refreshes the delicate surface of cars, boats, recreational vehicles, and patio furniture. It’s the mechanical elbow grease needed to efficiently remove dirt, oil, grease, road grime, and more.

Magic Wand

A wheel and rim brush attachment combines fine, nonscratching bristles with the washer’s pressurized spray to eliminate stubborn dirt, greasy rims, and even caked-on messes to return the rims to a showroom shine. It works on yard equipment, too.
Sandy Lindsey
Sandy Lindsey
Author
Sandy Lindsey is an award-winning writer who covers home, gardening, DIY projects, pets, and boating. She has two books with McGraw-Hill.