How to Pressure Wash a House

Co-authored by Varga Gulshani

Last Updated: January 13, 2022 References

Pressure washing, also known as power washing, involves using a high-velocity water spray to clean dirt and residue from the exterior of a house. This type of cleaning is a particularly important preparatory step before painting or re-painting your house. A clean surface allows new paint to last longer. You can use pressure-washing equipment on most types of housing material once you learn how to pressure wash a house.

Steps

1
Choose a pressure washer that is best for the job. Different housing materials can withstand various water pressures. The size, or spray power, ranges from 1,200 to 3,000 pounds per square inch (psi).
- Softer housing materials, such as painted soft-grain wood and aluminum, require a 1,200 to 1,500 psi model to prevent pressure damage. You may need a wide spray nozzle to disperse water pressure for even more vulnerable materials, like stucco.
- Stronger non-painted surfaces, such as vinyl, clean better with a more powerful 2,500 to 3,000 psi model. These models work the fastest.
- Select a pressure washer that has a detergent dispenser if you plan to use a cleaning solution.
2
Protect you house's exterior fixtures, like lights, landscaping shrubs and plants, from harmful water pressure. Cover with drop cloths or plastic covering and secure with duct tape.^{[1]
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- Move any outdoor furniture away from the house, too.^{[2]
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  Expert Source
  
  Varga Gulshani
  Residential Painting Specialist
  Expert Interview. 12 January 2021.}
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3
Manually scrub any visible mildew from the surface you are power washing with a brush.^{[3]
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4
Mix the cleaning solution and fill the pressure washer's detergent dispenser. Combine approximately 1 pound (.455 kilograms) of a non-phosphate concentrated cleaner for every 4 gallons (15.4 liters) of washing water.
5
Connect a garden hose hooked to your water supply to the pressure washer. When you are ready, turn on the water.^{[4]
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Expert Source

Varga Gulshani
Residential Painting Specialist
Expert Interview. 12 January 2021.}
6
Test how to pressure wash a house by holding the pressure washer nozzle with both hands about 3 feet (121.92 centimeters) from the wall. Move it in closer until you feel the spray is strong enough to remove dirt but not strong enough to cause damage.
7
Start at the top of the house and move down. Spray roof overhangs, under-hangs and gutters at an approximate 45-degree angle. Move the spray steadily from side to side.^{[6]
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8
Rinse from the top down with plain water from a garden hose.^{[7]
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Research source} Allow house siding to dry at least 2 days before painting.

Expert Q&A

Question

Does pressure washing damage the house?

Varga Gulshani
Residential Painting Specialist
Varga Gulshani is a Residential Painting Specialist and the Owner of Elegant Painting based in Washington. With more than 16 years of experience, Varga and his team specialize in residential interior painting, exterior painting, and cabinet painting. Varga and the Elegant Painting team have all received background and verification checks.

Varga Gulshani

Residential Painting Specialist

Expert Answer

Not exactly, but it can deal some damage. To avoid problems, move your patio furniture and other items away from the house. Then, seal windows and doors, adding towels under anything that you think might leak.
Question

What solution do I use?

Community Answer

You can use any kind of non-phosphate concentrated cleaner that you want, which can then be mixed with water per the instructions in the article.
Question

What is the best time of year to pressure wash my home?

Community Answer

Summer as the water will dry quickly. This will also prevent any lingering water from freezing and possibly damaging your home.

Warnings

Do not pressure wash your house if the exterior has lead-based paint. Homes painted before 1978 may have lead-based paint. If you are unsure, contact your public health department to determine whether your home contains lead-based paint.

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Use caution when operating a pressure washer. The high-velocity water spray can erode soft-grain woods, a stucco finish or mortar from between bricks if you hold it in one spot for too long. Never get closer than 12 inches from the wall's surface. Do not point it straight up or at windows, window frames, door frames, electrical units or people.

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Never pressure wash hardboard house siding. The moisture will damage the surface.

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