Cleaning grease stains from concrete requires removing loose debris, applying a degreaser at the label’s dilution, letting it dwell briefly, scrubbing with a stiff brush, and rinsing thoroughly to prevent residue buildup.
A concrete driveway or garage floor collects oil and grease fast—plain soap won’t cut it. Degreaser breaks down hydrocarbon stains so water can rinse them away, but skipping any step leaves the stain. Here’s the exact sequence that works.
How to Apply Degreaser on Concrete: The Step-by-Step Process
Every concrete degreaser follows the same core workflow. Start with prep, then apply the sequence that prevents wasted effort.
1. Clear and sweep the area. Remove vehicles, furniture, and plants. Sweep away loose dirt—a dirty surface blocks the degreaser from reaching the oil.
2. Check the temperature. Apply degreaser only when concrete is above freezing and fully thawed. Cold concrete slows the chemical reaction.
3. Pre-wet if the label says so. Some products call for a light misting. Follow the product’s specific instructions.
4. Mix and apply at the right dilution. This is where most mistakes happen. Catalina Chemical’s degreaser calls for undiluted use in a downstream injector or a 1:5 mix (1 part degreaser to 5 parts water) in a pump sprayer with a 1–2 minute dwell. Always read the product label.
5. Apply evenly and let it dwell briefly. Use a sprayer, mop, or brush for full coverage. Never let degreaser dry on the concrete.
6. Scrub with a stiff-bristled brush. Mechanical agitation lifts grease out of concrete pores. For larger driveways, consider a rotary brush attachment.
7. Rinse thoroughly. Use a hose or pressure washer. Hold the nozzle 12 to 18 inches from the surface with a wide spray pattern. Rinse until no suds or residue remain.
8. Inspect and repeat if needed. Old grease may take a second pass. Let concrete dry fully between treatments.
Choosing the Right Degreaser and Pressure Washer Settings
The product and equipment determine whether the job takes one pass or three. The table below shows two main approaches.
| Approach | Example Product | Key Specs |
|---|---|---|
| High-dilution concentrate for sprayer or mop | PROSOCO Cleaner/Degreaser | 1:4 heavy stain mix; 1:3 max dilution; 1–3 min dwell; 400–1,000 PSI rinse |
| Undiluted or 1:5 mix for downstream injector | Catalina Chemical Degreaser | Undiluted in reservoir; 1:5 in pump sprayer; 1–2 min dwell; rinse with standard pressure |
For a comparison of formulations, see our roundup of top concrete degreasers for driveways, garage floors, and patios.
Common Mistakes That Ruin a Degreaser Job
Three frequent errors to avoid:
Skipping the initial sweep. Dirt creates a barrier. A two-minute sweep saves a whole repeat treatment.
Guessing the dilution. Too strong wastes product and leaves residue; too weak does nothing. The label is the only reliable source.
Letting it dry on the surface. This causes white or hazy residue. Work in sections if the concrete is large; keep the surface wet for the full dwell time.
Using the wrong pressure-washer nozzle or too much PSI. A narrow tip can etch concrete. Stick with a 25–40° fan tip at 12–18 inches. Follow product PSI limits—
Not protecting nearby plants. Cover plants with plastic sheeting and rinse splashes immediately.
FAQs
Can you use laundry detergent or dish soap as a concrete degreaser?
A dedicated degreaser works faster and requires fewer repeat treatments.
How long should degreaser sit on concrete before rinsing?
Most degreasers need 1 to 3 minutes of dwell time—the label is the final authority. If the product starts drying, it creates a film that’s hard to rinse away. For thick grease, a second application is more effective than letting one sit longer.
Will degreaser damage concrete if left on too long?
The bigger risk is drying, which leaves white-looking residue. Rinse within the recommended dwell window.
References & Sources
- PROSOCO. “How to Remove Grease Stains from Concrete.” Specifies dilution ratios, dwell times, and pressure-washer settings for PROSOCO Cleaner/Degreaser.
- Catalina Chemical. “Catalina Chemical Degreaser Product Page.” Lists application methods and dilution instructions for pump sprayer and downstream injector use.
- Wolf Paving. “Cleaning Concrete: What Products Should You Use.” Provides general concrete-cleaning guidance, including pressure-washer PSI ranges and nozzle recommendations.