Ryan Cash

How many Gallons Per Minute do you need for a machine? What size pressure washer should I get? Is 3 GPM enough for residential cleaning?

I hear these questions a lot from contractors who are just getting into the industry. Many wonder if their small machine is adequate, and others wonder if some of the larger machines are too much.

For commercial applications The general rule of thumb is the more the better, with 8 GPM being about the minimum flow that would be usable. Most commercial work can be efficiently done with 10 or 12 GPM, but again, the more the better.

For residential work, it's not always so cut and dry. More is not always better.

  • Using really high flow machines can cause a few problems in a residential setting. Flooding areas with poor drainage and over applying chemical are the main problems with high flow machines.
  • On the reverse side, very low flow machines (2 GPM) just aren’t high enough to perform work efficiently. Typically 3 GPM is about the minimum suggested flow for residential work.
When I first started, I used a 3.5 GPM machine for years and never had a problem. Higher flow machines allow you to move faster, but it's certainly possible to be clean effectively with a 3 or 4 GPM unit.

5-8 GPM seems to be right at the sweet spot for residential cleaning. Several will suggest a 10 GPM but usually that is unnecessary, especially when it comes to house washing.

With House and Roof Washing, higher flow rates often lead to over application of chemicals and can result is wasted money and damaged landscaping.

5 GPM will still get work done quickly and efficiently and can be the perfect set up for residential.

For the BEST and ONLY All-In-One Residential Exterior Cleaning Machine that can get both high and low pressure cleaning with one tri-plunger pump, check out the RoofTec XCS500.

Our Sponsors