How to Clean and Degrease a Garage Floor

Garage floors take a beating. Oil drips, tire marks, rust stains, and years of tracked-in dirt layer into a grimy surface that makes the whole space feel neglected. The good news: a clean garage floor isn't just cosmetic. It's safer to walk on, easier to spot new leaks, and transforms how the whole room functions. A few hours of work with the right degreaser will pull your floor back to something usable—maybe not showroom, but clean enough that you actually want to work there. The key is matching your cleaning method to what's on the floor. Light dust and dirt need one approach; baked-on oil and transmission fluid need another. You don't need industrial equipment or expensive chemicals. A degreaser rated for concrete, a stiff brush, and water do the job. This guide walks you through it.

1. Clear the Floor First. Move cars, tools, boxes, and anything else out of the garage so you have full floor access. Sweep the entire floor hard with a stiff-bristled broom, working dirt and loose debris into piles and out the door. Don't skip corners and edges—this is where the most grit collects. The goal is bare concrete with no loose material before you apply any degreaser.
2. Apply Degreaser Strategically. Inspect the floor and identify problem areas—dark oil stains, rust marks, tire marks, or general grime. For localized heavy stains, apply degreaser directly to the affected spots and let it sit for 15–20 minutes to break down the oil. For the whole floor, dilute the degreaser according to the product label and spread it evenly with a roller or stiff-bristled mop. Work in manageable sections, about 8 by 10 feet at a time.
3. Work the Degreaser In Deep. Work the degreaser into the concrete with a stiff-bristled brush or deck scrubber, using firm circular motions. Focus extra effort on stained areas and traffic lanes where dirt has worn into the pores. You're not looking for shine; you're breaking the bond between grime and concrete. A scrub brush with a broom-style handle saves your back; a handheld tile brush works for smaller sections.
4. Flush Everything Away. Use a garden hose with moderate pressure or a pressure washer on low-to-medium setting (1500–2000 PSI for residential concrete). Rinse every scrubbed section completely, working from one end of the garage to the other. Push water toward the garage door or outside, letting it carry away loosened grime. If the water running off is still dirty, you haven't rinsed enough—keep going until it runs clear.
5. Repeat for Stubborn Stains. Once the floor dries (give it 2–4 hours in good weather), examine it for remaining stains. Older oil stains or transmission fluid often need a second pass. Apply degreaser again to problem spots, let it sit for 20 minutes, scrub, and rinse. Some stains won't vanish completely—concrete is porous and absorbs oil deep. Accept what comes out and don't force it.
6. Inspect the Final Result. Allow the floor to air dry fully (4–8 hours depending on humidity and temperature). Use a push broom or towels to speed drying if needed. Once dry, walk the floor and spot-check the results. You'll see any remaining stains clearly. If the floor is now acceptably clean for your use, you're done. If stains are still visible and bother you, plan a third treatment for deeper spots.
7. Seal for Long-Term Protection. For long-term protection and easier cleanup of future spills, apply a concrete sealer after the floor is completely dry. Choose a sealer made for garage floors and follow the label for coverage and drying time. Most seal in 2–4 hours and cure fully in 24–48 hours. A sealed floor sheds oil rather than absorbing it, making your next cleaning much faster. This step is optional but worth the modest cost if you want the floor to stay clean longer.