Degreasers and Heavy Soil: Getting Grease and Oil Off Floors With an Auto Scrubber
How to scrub grease, oil and heavy soil with an auto scrubber: degreaser types, dwell time, double scrubbing, squeegee and machine compatibility, and rinsing.
Key takeaways
- Heavy soil needs dwell time, so double scrubbing (scrub without vacuum, wait, then recover) beats one fast pass.
- Alkaline degreasers break down fats, while petroleum oils need solvents or strong emulsifiers.
- Solvent degreasers can swell gum rubber squeegees and seals, so check compatibility before use.
- Any degreaser above about pH 10 at use dilution needs a clear water rinse pass.
- Read the degreaser label and SDS and the scrubber maker's chemical compatibility guidance before filling the tank.
To remove grease and heavy soil with an auto scrubber, use a low-foam alkaline degreaser at the label rate, lay it down with the vacuum off, let it dwell 5 to 10 minutes, then scrub again and recover. This double scrub gives the chemical time to work. Follow with a clear water rinse pass on any floor where alkaline residue would be a slip or finish problem.
A degreaser is a cleaning chemical formulated to break down or emulsify oils, fats and greases so they can be suspended in water and recovered. Most floor degreasers are alkaline (typically pH 10 to 12 at use dilution), many add solvents, and some use enzymes or bacteria for slow-acting digestion of organic grease.
Know your soil before you pick a degreaser
"Heavy soil" covers very different chemistry. Matching the product to the soil matters more than buying the strongest one.
| Soil | Where you find it | What works | What does not |
|---|---|---|---|
| Cooking oil and animal fat | Kitchens, food plants, cafeterias | Alkaline degreaser (saponifies fats), warm water, dwell time | Neutral cleaner alone |
| Polymerized or baked-on grease | Around fryers and cook lines | Strong alkaline degreaser, grit brush, repeated double scrubs | One fast pass |
| Petroleum oil, hydraulic fluid | Warehouses, forklift aisles, loading docks | Degreaser with solvent or strong emulsifiers | High pH alone |
| Cutting fluids and machining oils | Manufacturing plants | Industrial degreaser, often solvent blended | Neutral cleaner |
| Tire marks | Warehouses, parking garages | Alkaline cleaner plus aggressive brush or pad | Chemistry alone |
| Protein soils (blood, dairy, meat) | Food processing, healthcare kitchens | Alkaline or enzyme cleaner, cool to warm water | Very hot water, which can set proteins |
| Compacted dirt and grime | Entrances, docks, garages | General alkaline cleaner, grit brush, slow passes | Fast passes at high speed |
Degreaser types compared
| Type | How it works | Strengths | Watch-outs |
|---|---|---|---|
| Alkaline (builder-based) | High pH breaks down fats and suspends soil | Strong on kitchen grease, widely available, often low foam | Softens floor finish, can dull aluminum, skin and eye hazard |
| Solvent-blended (glycol ethers, citrus d-limonene) | Solvents dissolve oils, surfactants lift them | Good on petroleum and mixed oily soils | Can swell gum rubber squeegees and seals, odor, ventilation |
| Enzyme or bacterial | Enzymes or microbes digest organic grease over time | Good for grout lines and drains, lower hazard | Slow, needs dwell time, sensitive to hot water and harsh chemicals |
| Emulsifying non-solvent | Surfactants wrap oil droplets in water | Lower odor, often safer on rubber | May need more dwell and agitation |
The SDS will tell you which category a product falls into. Look at the composition section and the pH listed in the properties section.
Will it hurt the machine?
This is the question dealers rarely get asked until a squeegee fails. Check four parts against the scrubber manual's chemical guidance.
- Squeegee blades. Natural gum rubber (often called linatex or gum) gives an excellent wipe but swells and softens in oils and many solvents. Polyurethane and some oil-resistant compounds hold up much better in kitchens and oily plants. See squeegee blade materials.
- Tanks, hoses and seals. Most polyethylene tanks tolerate typical floor chemicals, but some seals and hoses do not tolerate strong solvents.
- Pumps and solenoids. Some solution pumps and dosing systems are rated only for certain pH ranges or viscosities. See chemical dosing systems.
- Metal parts. Strong alkalis can attack aluminum. Rinse the deck, squeegee assembly and tanks with clear water after degreasing jobs.
The double scrub procedure
Single-pass scrubbing gives the chemical only a few seconds of contact before the squeegee picks it up. That is enough for dust, not for grease. Double scrubbing separates application from recovery.
- Sweep or dust mop. Loose grit and debris clog the recovery system and dull pads.
- Pre-treat the worst spots. Spray degreaser on heavy grease patches, fryer zones or oil stains with a pump sprayer.
- First pass, vacuum off. Run the scrubber with brushes and solution on, squeegee raised and vacuum off. Cover a manageable area, roughly what you can come back to within 10 minutes, and do not let it dry.
- Dwell. Wait 5 to 10 minutes, or the time on the label. Barricade the area, it is extremely slippery.
- Second pass, vacuum on. Scrub again with squeegee down and vacuum on, at slow speed. Use a fresh pass of solution if the first one has gone thick.
- Rinse pass. Run clear water (or the label's recommended neutralizer) with the vacuum on. Check the floor with the tests in residue and rinsing.
- Clean the machine. Empty and rinse the recovery tank, rinse the squeegee and brushes, and leave the recovery lid open to dry.
On a walk-behind, the slower travel speed for heavy soil matters. Our productivity model uses about 175 ft/min for routine walk-behind work, but heavy soil runs often drop to half that, plus the extra passes. Budget roughly two to three times the routine time for a true double scrub with rinse, and check your own numbers with the productivity calculator.
Mechanical action does half the work
Chemistry and agitation trade off against each other. If a degreaser is not working, change the mechanical side before raising concentration.
| Lever | Change | Effect |
|---|---|---|
| Brush or pad | Polypropylene to grit (abrasive) brush, or red pad to blue or green | Much stronger scrubbing on textured or grouted floors |
| Down pressure | Raise one step | More contact, more wear on soft floors |
| Speed | Slow down | More brush revolutions per square foot |
| Dwell time | Add 5 to 10 minutes | Lets the chemical penetrate before recovery |
| Water temperature | Warm, within the machine's rating (104 F to 140 F depending on model) | Softens fats, but protein soils prefer cool to warm |
| Concentration | Step up within the label range | Last resort, raises residue and foam risk |
Use the pad selector and brushes and pads to choose the agitation level, and down pressure for the pressure trade-offs. Before turning up the heat, look up your machine's limit in hot water in a floor scrubber: some walk-behinds allow only 104 F (40 C).
Where degreasers do not belong
- Finished VCT and other floors with acrylic finish. Routine degreasing dulls and softens the finish. Use a neutral cleaner and save degreasers for top scrub or strip work.
- Rubber flooring. Solvents and petroleum-based products can swell or discolor rubber; follow the flooring maker's guidance.
- Natural stone. Strong alkalis can damage some stone and sealers; use stone-specific products.
- Daily general cleaning. If a building needs degreaser every night, look at entry matting, kitchen spill control and frequency instead.
Heavy soil field checklist
- Soil identified (fat, petroleum, tire, protein or mixed)?
- Product labeled for automatic scrubber use and low foam?
- Squeegee and seals compatible with the product?
- PPE, ventilation and wet floor signs in place?
- Area sized so the first pass will not dry before the second?
- Rinse pass planned, and recovery tank emptied before it reaches the float?
- Defoamer ready for the recovery tank if needed (see defoamers and foam control)?
Frequently asked questions
Can I use a kitchen degreaser in my floor scrubber?
Often yes, if the label allows automatic scrubber use, the product is low foam, and your scrubber maker's chemical compatibility guidance allows it. Check the squeegee material, because some degreasers swell gum rubber blades.
How long should a degreaser dwell before I recover it?
Five to ten minutes is a common range, but follow the product label. Do not let the solution dry on the floor, because dried degreaser leaves a residue that is harder to remove than the original soil.
Why does my squeegee swell after degreasing?
Gum rubber blades absorb oils and many solvents and become soft and wavy. Switching to an oil-resistant blade such as polyurethane and rinsing the squeegee after each degreasing job usually fixes it.
Do I need to rinse after using a degreaser?
On most floors, yes, if the use solution is around pH 10 or higher. A clear water rinse pass removes alkaline residue that would otherwise make the floor slippery, sticky and quick to re-soil.
What is the best way to remove forklift tire marks?
Combine an alkaline cleaner with stronger agitation, such as a grit brush or a more aggressive pad, at slow speed. Tire marks respond more to mechanical action than to extra chemical.