Pro Tips: Picking a Pressure Washer

Pressure washers are a powerful cleaning tool for the professional painting contractor. In this article, we go over the basics you should know before you make this important investment.

Cleaning units

Cleaning units gives the contractor a measure of unit performance (efficiency) to compare one unit to another. Cleaning units is calculated by multiplying PSI and GPM. Example:

  • 3200 PSI x 2.4 GPM = 7680 cleaning units
  • 4000 PSI x 3.5 GPM = 14000 cleaning units

The 4000 PSI unit cleans 50 percent faster than the 3200 PSI unit. Not better, but faster. Cleaning units do not determine quality of the unit. Quality is determined by the type of pump and the components of the pump.

Belt drive

Most commonly found on industrial models, a belt-driven pump is ideal for cleaning applications requiring 20 or more hours of use per week. The belt connecting the engine or motor with the high-pressure pump dissipates the heat and vibration, minimizes the wear and thus the repair on key components, and extends the life of the pump by reducing the RPM demand.

Direct drive

For applications not requiring more than 20 hours of use per week, direct driven pumps are more commonly used. The pump is directly coupled to the engine or motor causing the pump to spin twice as fast as the belt drive models. Although these models are not recommended for heavy, consistent usage they are a lower cost alternative to more expensive, belt driven models.

Is time a factor?

A heavy-duty pressure washer can cut cleaning times in half. Shorter cleaning time means less labor, which equals more productivity.

Our pick for paint pros

The Mi-T-M® Job Pro Aluminum 4000 PSI contractor-duty pressure washer is the ideal model for paint preparation, concrete and brickwork, heavy mold and mildew removal, and large deck and surface restoration.

The lightweight, corrosion-resistant aluminum frame makes this powerhouse extremely mobile and durable. Built for up to 20 hours of use per week, it is powered by a 389cc Honda overhead valve engine and high-performance direct drive pump.

Learn more

Visit your local Sherwin-Williams store for expert guidance on the best pressure washers for your jobsite needs. You can also find more information at

Mi-T-M pressure washers are available at Sherwin-Williams stores. Visit the Sherwin-Williams contractor website for a full list of painting equipment and supplies.