How to Use a Floor Scrubber (Auto Scrubber), Step by Step

To use a floor scrubber, sweep the floor first, fill the solution tank with water before any detergent, then lower the pad and squeegee and walk forward slowly with each pass overlapping about 2 inches. When you finish, drain and rinse the recovery tank and leave the lid open to dry.

That covers the basics, and if your floors already come up clean and dry, you can stop reading here. The rest is for new operators, and for anyone whose auto scrubber somehow leaves the floor looking worse than a mop would.

Before you start: clear, check, fill

Do you have to sweep before using a floor scrubber?

Yes, almost always. Floor scrubbers are engineered for wet cleaning, not for collecting debris, so the grit, staples and hair you leave behind either scratch the floor under the pad or collect along the rubber blade at the back, which is where most streaks begin. Tennant says it plainly in its T3 operator training video: pick up large debris and clear the area before scrubbing, to help prevent streaking and damage to your machine.

Experienced custodians add one additional habit worth copying. A treated dust mop grabs the fine hair that a dry one pushes around, so the blade stays clean for longer during the cleaning run. Cylindrical and CRB machines don't change that rule. Their brushes do flick fine debris into a tray or debris hopper as they scrub, but both the Tornado Vortex manual and the Powr-Flite Multiwash manual still tell you to clear the floor of debris before use, and rocks, zip ties and pallet wrap will jam the brushes.

Before you turn the key, run through a quick maintenance check of three things. The blade should be clean and undamaged, your pad or brush should be free of embedded grit, and the float screen inside the recovery tank should be clean and in place.

Which pad or brush should you use?

Start with a red pad on finished floors, and only go darker when you have a genuine reason. Pads and brushes both come in grades, and pads run from white, the softest, through red, blue and green to black, which is reserved for stripping. Red is the everyday cleaning pad for surfaces like VCT, while green removes the top layer of floor finish before a recoat.

Brushes are usually the better choice on concrete, textured tile and grout lines, because the bristles reach into low spots that a flat pad simply rides over. Scrub brushes also last far longer than pads, which matters when you are cleaning the same floor five nights a week. The mistake you want to avoid is a pad that is too aggressive for your floor type. Operators report permanently dulling painted epoxy floors with green pads, and floor technicians describe the same damage on freshly waxed commercial floors. Our guide to disk, cylindrical and orbital scrub heads covers which deck suits which floor.

How to use a floor scrubber, step by step

1. Fill the solution tank with water first, then add detergent at the label rate. Pouring water on top of soap produces foam before the tank is even half full.

   

2. Turn the key on and lower the scrub deck. Leave the brush pressure and speed settings at standard unless your manual recommends otherwise for your floor type.
3. Lower the squeegee. On many machines this also starts the vacuum automatically.

   

4. Set the solution flow low. Tennant recommends the lowest settings that still give you the cleaning results you expect, because extra water mostly gives the pickup system more work.
5. Walk forward at a slow, steady pace, overlapping each pass with the previous one by about 2 inches.

   

6. Watch the pickup behind you. You want a dry path behind the machine, and if pickup stops or the vacuum motor suddenly changes pitch, the float has shut off, so stop and empty the dirty side.

Don't back up with the squeegee down. Most walk-behind and ride-on floor scrubbers only recover water while moving forward, and Tennant's rule for reversing is to raise the squeegee before you change direction. The exception is compact machines designed to clean in both directions, such as the Clarke Vantage 14, so check your manual before assuming either way.

Keep the machine moving continuously, too. A scrubber parked in one spot with the pad spinning keeps laying down cleaning solution and grinding on the same small patch of floor.

Which direction should you work?

Make one lap around the perimeter first, then fill in the middle with straight overlapping passes that finish at your exit. Starting your floor scrubber at the walls and working your way in gives you a clean border to turn on, and finishing at the door means you never walk your own footprints back across a floor you just cleaned.

Put your wet floor signs out before the first pass. Walk-through traffic is the main safety risk during commercial floor cleaning. Slip safety is your responsibility as the operator, and early signs keep people off a surface they can't see is wet.

When does a floor need a double scrub?

When one pass leaves the floor dull or sticky, and a second ordinary pass doesn't improve it. Tennant describes the method in a short demonstration: scrub with the squeegee up so the cleaning solution stays on the floor and dwells, then scrub again with the squeegee lowered to recover everything. An experienced floor technician on Reddit describes the same routine, shutting the solution off on the second pass because the floor is already wet.

Double scrubbing takes longer, but it is often the difference between a floor that looks mopped and one that looks restored.

How much soap goes in a floor scrubber?

Usually less than you think, and more chemical never means better cleaning. Use a low-foam detergent made for auto scrubbers, mixed at the dilution printed on the label. A typical label, such as Kärcher's neutral floor cleaner, calls for 1 fluid ounce per gallon for daily cleaning and up to 2 ounces for heavier soil. In a 10 gallon solution tank, that works out to 10 to 20 ounces, roughly one and a quarter to two and a half cups, not a generous pour.

Overdosing leaves a residue that looks hazy, feels sticky underfoot, and attracts new dirt faster than the floor you started with. Custodians consistently report the same fix for it: run one pass with plain water, then cut the dose back.

Plain water is also a legitimate choice on lightly soiled floors, and some machines, such as Tennant's ec-H2O models, are specifically designed to clean without any chemical. On greasy or sticky commercial floors, however, a proper scrubber detergent still earns its place in your solution.

Never use dish soap or household cleaners in your floor scrubber. They foam heavily, and foam can slip past the float that normally shuts off the vacuum when the tank is full, carrying moisture straight into the vacuum motor. If you notice foam building, pour a foam control solution into the recovery tank, exactly as Tennant's training video advises. Operators on Reddit keep defoamer on hand for this reason, and a capful of fabric softener works in an emergency.

What to do when you're done

Drain the dirty side, rinse it with clean water, and clean the float screen and debris tray before you leave. Then leave the lid open, every time. Floor technicians describe exactly what happens when somebody closes the lid on a full load of dirty water: within days it smells terrible, and within weeks it grows black mold you may never fully remove. An open lid lets everything dry out and keeps your vacuum motor from sitting in damp air overnight.

Wipe down the blade, rinse your pads or brushes, and drain the solution side if the machine won't be used again soon, because detergent left sitting settles in the lines and the filter.

Then charge your battery, and do it properly, because this is the maintenance step that decides how long your machine keeps running:

• Charge after a real shift. Tennant says to recharge only when the machine has run for 30 minutes or more, and never to leave batteries discharged for long. Trojan, the battery manufacturer, says to charge fully after each period of use. Both point the same way: plug your machine in after real work, not after a five minute touch-up.
• Let the charger finish its cycle. Unplugging mid-charge to squeeze in another run is hard on lead-acid batteries. One custodian traced a scrubber's runtime falling to about 30 minutes directly to that habit, and with new batteries and full charges, the same machine ran well over two hours a year later.
• You don't need to run your battery flat first. Trojan states that lead-acid batteries don't develop a memory and don't need full discharges.
• Water flooded batteries after charging, never before. Check that the plates are covered before you plug in, then top up with distilled water once charging is complete. Sealed AGM and lithium batteries need no watering at all. Our flooded battery maintenance guide covers the full routine.

This routine maintenance, along with the cleaning steps above, takes about five minutes at the end of your shift, and it separates the floor scrubbers that last for years from the ones that smell bad and die young.

Mistakes new operators make

Most cleaning problems in the first week come from the same short list of habits, and none of them has anything to do with the machine itself.

• Skipping the dust mop, then blaming the machine for streaks.
• Stopping in one spot with the pad still spinning.
• Using a green or black pad on a finished floor, unless you mean to remove finish (green for a top scrub, black for stripping).
• Pouring in extra chemical for a "better" clean.
• Backing up with the squeegee down.
• Closing the lid on a full recovery tank.
• Unplugging the charger early, day after day.

None of these requires a new part or a maintenance visit, and most of them cost you nothing to correct. If your floor scrubber still leaves streaks or water behind after you've fixed all of them, our floor scrubber troubleshooting guide walks through the causes in order.

Not sure your machine suits your floors? Send us your square footage and floor type through our contact page, or call (855) 601-5678, and you'll get an honest answer about whether the problem is your machine or your method. If it turns out to be the machine, our range of commercial floor scrubbers covers walk-behind, ride-on and compact models.

Common questions

Is scrubbing better than mopping?

Yes, for any floor large enough to justify purchasing the equipment. A mop spreads dirty water around and leaves it to dry on the surface, while a scrubber vacuums the dirty solution into its recovery tank on the same pass. If you are weighing up the cost, our guide on whether auto scrubbers are worth the investment runs the numbers for you.

Can you use a floor scrubber on a wood floor?

Occasionally, on properly sealed hardwood, with a soft pad and minimal water flow, and only if the flooring manufacturer allows it. Moisture that gets between boards causes swelling and warping, and custodians disagree sharply about scrubbing wood gym floors at all, so check your floor manufacturer's care guide before your first pass.

Related reading: Types of floor scrubbers · Floor scrubber batteries compared · Warehouse floor cleaning, step by step · Floor buffers vs burnishers · Commercial floor scrubbers · Compact floor scrubbers

Written by Rod Michelini, OneUp Cleaning. Disclosure: we sell Tornado, which is Kärcher-affiliated, as well as Clarke and other brands mentioned here. We don't currently sell Tennant, whose training material is cited throughout because it is the clearest published source on operating these machines.