Best pressure washer surface cleaner, matched to the machine you own

Our concrete roundup says a surface cleaner is the real upgrade on flatwork and then stops, which has been a gap on this site for as long as that page has existed. Filling it turned up something more useful than a product ranking: every surface cleaner on the shelf is rated for two to four times the water flow a homeowner pressure washer actually delivers, and flow is the spec that makes the head spin.

The short answer

Flow spins the head. Pressure does not.

A surface cleaner is a shroud with two jets on a rotating bar. The jets are angled off-center so that the water leaving them pushes the bar round — the same principle as a lawn sprinkler. What pushes it is the volume of water moving through, which is gallons per minute. Pressure decides how hard each jet strikes the concrete once it gets there.

That is why a surface cleaner's advantage over a wand is coverage rather than aggression, and why the GPM rating on the box matters more than the PSI one. It is also why only one of the three makers here publishes a GPM figure at all.

The three, on published figures

1. Greenworks 15" 5210902 — sized to the machines people own

Greenworks publishes a 15 inch cleaning width, a 3,100 PSI maximum, a 1/4 inch quick-connect, plastic and brass construction, a dual-nozzle rotating head, and a box containing the cleaner, a 12 inch wand extension and the owner's manual. It publishes no GPM, no weight and no warranty term.

Why it leads: its ceiling is 3,100 PSI against its own brand's strongest washer at 3,000 — a 3% margin. That is the most honest sizing of the three, and it is what you want from an accessory: built for the machine rather than for a number no homeowner unit reaches. The wand extension in the box is the other reason; a surface cleaner without one puts your hands at an awkward height for the whole job.

Who should skip it: anyone with a gas machine above 3,100 PSI, which is the lowest ceiling here; and anyone who wants a metal body, since plastic and brass is what Greenworks publishes.

#ad Check the Greenworks 15" Surface Cleaner with 12" Wand Extension price on Amazon — how we're funded.

2. Westinghouse PWSC — the only published flow rating

Westinghouse publishes a 15 inch cleaning path, 3,400 maximum PSI, 2.7 maximum GPM, a 1/4 inch quick-connect, dual rotating jets, a weight of four pounds, dimensions of 15 x 15 x 4 inches, compatibility with its own WPX2700, WPX3200 and WPX3400 machines, ratings for concrete, brick, wood and other outdoor surfaces, and a 180 day limited warranty. It publishes no material.

Why it is here: the GPM figure. It is the single most useful number in this category and Westinghouse is the only maker that states it, which makes this the one attachment whose fit to your machine you can actually evaluate before buying. Four pounds is also the lightest here by 2.8 lb, which matters on a tool you drag across 600 square feet of driveway.

Who should skip it: anyone expecting it to last. A 180 day warranty is the shortest commitment any maker in our entire registry offers on anything, and this is a product whose only moving part spins under load. Also note that all three named compatible machines are Westinghouse gas units and none is in our registry, so the stated fit is to a family of machines we hold no specs for.

#ad Check the Westinghouse PWSC Universal 15" Surface Cleaner price on Amazon — how we're funded.

3. Sun Joe SPX-SC14 — stainless, wheeled, and 13 or 14 inches

Sun Joe publishes 4,000 maximum PSI, 4.0 maximum GPM, a 300 F (149 C) maximum water temperature, stainless steel construction, four 1.9 inch wheels, 6.8 lb, dimensions of 13.4 x 6.1 x 13.2 inches and a 1/4 inch quick-connect. It publishes no warranty on the product page — and its spec table states a 13 inch extension where its own product description says 14 inches, on a product whose model number is SC14.

Why it is here: it is the only attachment of the three that publishes a weight, dimensions, a wheel size, a material and a water-temperature rating — five figures the others largely leave blank. Four wheels rather than a skirt alone is a real difference on rough concrete, and stainless steel is the only metal body in the group.

Who should skip it: anyone with a 1,800 PSI corded washer. You are paying for a 4,000 PSI and 4.0 GPM ceiling that your machine will use less than a third of, and the 15 inch heads cover more ground per pass. The width discrepancy is also worth taking seriously as a signal: it is a small error, on the one spec the model name is built from.

#ad Check the Sun Joe SPX-SC14 Universal Surface Cleaner price on Amazon — how we're funded.

Which of our washers each one suits

Using one without leaving marks

1. Test on a square foot out of sight. A surface cleaner holds the jets at a fixed height, which removes operator error and removes your ability to back off. Find out what it does to your concrete before you find out across the whole drive.
2. Overlap each pass by about a third. The shroud's edge cleans less than its center, and the band that shows up afterwards is the one you did not overlap.
3. Move at a steady pace, not a slow one. Dwelling leaves a clean patch that makes everything around it look dirty. Evenness is the entire reason you bought the thing.
4. Keep it off vertical surfaces. These are flatwork tools. For siding, use a wand and a wide nozzle — see best pressure washers for siding, which covers why more pressure is the wrong answer on a wall.
5. Use the right tip on the wand for edges. A surface cleaner cannot reach the last inch against a wall or a bed. The nozzle that can is in our nozzles guide.

Who should skip all three

• Anyone without flatwork. No driveway, no patio, no garage floor, no sidewalk — no reason. A wand does paths and steps.
• Anyone washing timber or siding as the main job. Decks and fences and siding are both wand jobs, and both pages argue for less pressure rather than a different attachment.
• Anyone on a cordless washer with a small driveway. The Greenworks 60V publishes 30 minutes of runtime; a surface cleaner uses the same water either way, so the attachment buys evenness, not time. The trade is in corded or cordless.
• Anyone who has not read what pressure does to concrete. A surface cleaner is more consistent than a wand, which also makes it more consistently damaging on soft or old flatwork. Pressure washing a driveway covers it.

What we cannot tell you

We have not used any of these three attachments. None of the three publishes a minimum flow or a minimum pressure, so we cannot tell you the point at which a head stops spinning fast enough to be worth having — which is the single most useful figure the category could publish and none of them does. Only Westinghouse publishes a GPM rating, so for two of the three we cannot assess the flow match at all. Greenworks publishes no weight and no warranty; Sun Joe publishes no warranty; Westinghouse publishes no material. Sun Joe's own page disagrees with itself about whether the cleaning path is 13 or 14 inches, and we have no way to resolve it. None of the three publishes a coverage rate in square feet per hour, so the "4X faster than a wand" style of claim cannot be checked against anything. And we have measured no cleaning result on any surface, which is why this page ranks on fit to your machine rather than on how clean your driveway ends up.