How To Use A Pressure Washer With Soap And Detergent

Use a power washer with soap

Use a power washer with soap

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While a power washer can be used to directly wash off dirty items around your home, sometimes the blasting power isn’t enough to get rid of the dirt on it’s own.

That’s when it’s time to use your pressure washer with soap.  You might not have even known this is possible, but it’s one of the features of most every electric or gas power washer.

Using soap and/or detergent with your best pressure washer will help remove stains and improve the cleaning process.

When should you use soap and when detergent with your pressure washer?

Soap is made from natural fats and oils derived from plants and animals. It is therefore usually biodegradable and can be washed down the storm drains. Many detergents are also biogradable – though check first if your drains lead to a river, lake or the ocean. Some detergents can harm fish.

Soap is an emulsifier that activities the mixing of the oily debris with water. Detergents are chemically manufactured and are surfactants. Surfactants lower the water surface tension so that the water interacts with the oily grime.

Detergents can be used with hard (untreated water with calcium and magnesium impurities) and soft water. Soap, however, will leave behind calcium carbonate residue if used with hard water.

Never use detergents with bleach in your power washer because it will damage the washer pump.

Which detergent to use?

Generally, an all-purpose detergent will be sufficient to use. For best results, however, use the detergent designed for that specific application. Here are some suggestions to consider when choosing a cleaning solution for a specific surface:

  • Deck and fence detergents are designed to remove grass stains and dirt from the wood.
  • Household cleaning detergents remove dirt without fading color. It can be used for pressure washing sidings.
  • Boat detergents will clean off algae deposits on your boat.
  • Cars require a detergent that removes dead bugs and road dirt.
  • Garage driveway needs a detergent that will remove the oil stains.
  • Foamy pressure washer detergents may work for the concrete driveway but not for the vehicles.
  • Be mindful that dishwashing soaps may sting your eyes or pets and children nearby.

Concentrated cleaning solutions should be diluted with water.

Detergent Tank or Water Bucket

If your pressure washer doesn’t have a detergent tank, then you’ll need a bucket for the detergent hose.

Detergent Tank

  • Fill the tank with detergent.
  • Turn the valve to “On” to apply the cleaning solution.

Water Bucket

  • Make sure the cleaning solution injection tube is attached to the pressure washer pump.
  • Insert the other end into the bucket with the diluted cleaning detergent.

Detergent Brush or Gun

  • With some pressure washer brushes, you apply the cleaning solution directly onto the brush for deeper cleansing.
  • Apply the cleansing solution bottle attachment to the side of the pressure washer gun; it works the same way as the detergent tank.

Clean With The Pressure Washer

  • Before you clean with the detergent, use the pressure washer to get rid of loose dirt and debris. Then the cleaning solution cleanses the deeper stains.
  • Use a low-pressure nozzle.
  • Spray upward and overlap slightly to avoid streaks and missing areas.
  • Wait 5-10 minutes but don’t let the detergent dry.
  • Switch the detergent valve to “”
  • Flush remaining detergent from the pressure washer.
  • Now use a high-pressure nozzle to clean the surface.
  • Rinse clean from the top downward to avoid streaking.

Although most detergents and soaps are biodegradable, it is a good idea to spray surrounding areas with clean water. It will remove soap and detergent from surrounding plants.

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  1. Perfect post very in depth knowledge so the job gets done right. thank you i will be using this information for my own business.

    1. James Greyser says:

      Glad we could help!

  2. Bryson Owens says:

    I really appreciate you warning me about the leftover residue that soap can sometimes leave behind. My wife and I are trying to clean up our home and property soon so that we aren’t embarrassed when guests come over. I love the idea of washing the patio and sidewalks to get all the dirt off.

    1. James Greyser says:

      Thanks for the comment!