How many gallons does it take to soft wash a house?


Estimating how many gallons to soft wash a house:

This is for General information and obviously we would recommend hiring a professional company to complete the work.

Soft washing involves using low pressure water, a surfactant and Sodium Hypochlorite to Clean off dirt and grime from your building. Depending on the pump volume for example a 5.5 gallon per minute pump will require up to 5.5 gallons of water to operate. If it takes you one hour to spray your house, you will have used approximately 330 Gallons (5.5*60 minutes) spraying your house for the entire hour at full speed. This number will go up or down depending on the Pump volume per minute, which should be located on your pump or in your owners manual.

Estimating how much Sodium Hypochlorite follows the same formula. The difference will be what your mixture is being downstream. if you are using 50/50 (50% SH/50%water) then you will be using approximately 2.75 Gallons of SH per minute or what ever your pump is rated for and approximately 2.75 GPM of water. The flow rate is based off of optimal pump production at full speed. Adjusting your rated based on the operating speed is required. Estimating this is based on how much time you spend actually spraying with the mixture.

Similarly when using a surfactant to downstream you will follow the same formula. If you are running 40/10/50 (40% Water/10% Surfactant/50 % SH). 5.5 gallons per minute will be 2.75 gpm SH, 1.1 gpm of Water, and the remaining will be surfactant (1.65 gpm). This is an Extreme example for reference.

IT is important to realize that down-streaming is AFTER the pump if using a pressure washer. You do NOT want to run SH or anything else other then water through a pressure washer. This can damage the pump, pump seals and etc.

These settings should only be used if you are soft washing Brick or Stucco.

Check out our page to give you more information on the POWER WASHING DOS AND DON’TS


For a normal Vinyl house or combination of, you can pre mix about 10 oz of your choice of surfactant for every 5 gallons and downstream that mixture. It does not need to be a “HOT” mixture if you do not need it. Our recommended Procedure is to BATCH MIX. You can wash approximately 4000 sq. feet with this 5 gallon Mixture if used correctly. Downstreaming as described using a pump and pulling directly into the hose from containers and mixing valves may result in using more chemical then what is required to complete the job if you do not know what you are doing. 

ALWAYS follow the recommended Personal Protective Equipment Guidelines for whatever Chemicals you are using.


Complicated mixtures? You may want to call a professional pressure washing/ soft washing company to complete your job.

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