How to choose a pressure washer
What you need to consider before buying this tool
Removing a summer’s worth of crud from the deck or prepping the side of the cottage for painting is a lot faster, easier, and—admit it—more exciting with a pressure washer.
But you need the right one, with enough power to drive away dirt but not so much that you drill holes in your wood. Here’s how to choose:
First, pick your PSI
Pounds per square inch (PSI) is the blasting strength of the water. In general, a PSI of 1,000 to 1,700—considered light duty—works for cleaning patio furniture, steps, small decks, cars, and boats (you’ll spend between $150 and $240). A PSI of 1,800 to 2,500 has the power to efficiently handle large decks, stone patios, and fencing (about $250 to $550).
To clean siding, you’ll need a PSI between 2,700 and 3,200 (up to $800). Pressure washers also have a gallons-per-minute (GPM) rating—the volume of water flow—which affects how fast you can clean, and a rating for cleaning units (CU)—the combined cleaning speed and power. (The CU is the unit’s PSI multiplied by its GPM.) A higher CU means you can clean more stuff, more quickly.
Next, go gas or electric? Hot or cold?
Electric-motor units are not as powerful as gas-engine units, and they’re not as portable on account of the cord, but they are lighter and more compact.
Gas units give off fumes —not good if you plan to pressure wash in an enclosed area, such as a boathouse.
Hot-water washers clean more effectively, but the burner or coil system tacks on even more weight.
Using job-specific pressure-washer detergent may also help tackle especially tough or greasy tasks. However, if you plan to use a pressure washer only for small jobs or, say, for a couple of hours a week, an electric cold-water unit should be enough.
Now add nozzles
You can easily ramp up (or dial down) the cleaning power by changing the nozzle. Some pressure washers are sold with different spray tips included, or you can buy the tips separately.
The larger the spray angle, the wider and less powerful the spray; a zero-degree nozzle gives a narrow, solid stream of water. That’s enough to peel paint or scar soft wood if you get too close. So don’t point a pressure washer at your new cedar bench. Or your foot.
This article was originally published on September 1, 2010