Oil sinks into concrete's pores, so speed and patience matter. This guide covers fresh spills, old stains and what to do before you seal.
Concrete looks solid but is full of tiny pores and capillaries. Oil and grease wick into them, and the longer a spill sits, the deeper it goes. An unattended spill can also begin to degrade the surface over time, which is another reason to act quickly.
Fresh stains come out far more easily than old ones. Old, deep stains often need several rounds of treatment, and some leave a faint shadow even after good cleaning. Set expectations accordingly, especially on a lightly colored or sealed surface.
Fix the leak before cleaning, or you will be doing the job again. Then soak up as much standing oil as you can. Cover a fresh spill with an absorbent such as clay-based cat litter, sawdust or a product sold for automotive spills. Press it in with a shoe or board, leave it for several hours or overnight, then sweep it up.
Dispose of used absorbent properly. Oil-soaked material may be regulated as household hazardous waste in some places, so check with your local waste agency rather than putting it in the regular trash without asking.
With the loose oil removed, move on to a cleaner. Two common approaches are a commercial concrete degreaser and a household approach using powdered laundry or dishwasher detergent.
Deep stains rarely come out in one pass. Repeat the process several times, letting each round work. If a faint stain stays, a poultice may help. A poultice is a paste of absorbent powder and a solvent or cleaner that is spread over the stain, covered and left to dry, pulling oil out as it does. Poultice products for concrete are sold with instructions, and following them closely matters because the solvents can be flammable or irritating.
Avoid aggressive tools that damage the surface. A high-pressure washer can help with rinsing, but holding the nozzle too close can etch the concrete, leave marks and expose aggregate. Acid washing for oil is not recommended, since acid does not dissolve oil and can damage the surface.
Sealers and coatings do not bond well to oily concrete, and sealing over oil can lock in a stain or cause the sealer to fail. Clean the slab thoroughly and let it dry before sealing. See how to seal a concrete driveway for the full process.
Colored and stamped surfaces are more delicate. Cleaners can lighten color or dull a sealer, so test in a hidden spot first. If a decorative surface is stained, ask the installer or a professional what is safe to use.
Oil is not the only mark that shows up on a driveway. Tire marks, rust from furniture or fertilizer, leaf and tannin stains, mildew and paint drips each respond to different treatments, and what works on one can damage the surface or set another stain. Identify the stain first, then check the label of any product for use on concrete, and test a hidden spot before treating a visible one.
For most stains the principles are the same as for oil. Act early, start with the gentlest method and rinse thoroughly. Avoid mixing chemicals, and keep sealers and decorative finishes in mind, since cleaners that suit plain concrete can dull or lighten a sealed or colored surface.
If a stain will not come out, or if the surface is stained across a large area, a professional cleaning, resurfacing or a new sealer may be the better path. We can look at photos if you send them with a quote request.
Hire help when the stain is large, very old or on a decorative surface, or when repeated treatments have not worked. Professionals can use stronger products and equipment, such as hot-water washing or specialty poultices, and they know how to avoid damaging a sealer or color.
A badly stained, worn driveway can also be resurfaced or sealed with a product that hides what cleaning cannot remove. That is a cosmetic fix, not a deep cleaning, so be clear about what you expect. Send photos with a quote request, and we can say whether cleaning, resurfacing or replacement makes the most sense.
A sealer makes cleanup easier because oil beads on the surface for a while instead of sinking in, though it does not make concrete stain-proof. Fix leaks, park on a drip mat or tray, and wipe spills quickly. Regular cleaning keeps small drips from building up.
If stains keep coming back or the surface is badly worn, our repair, leveling and sealing page explains resurfacing and sealing for existing slabs. Because sealed driveways are easier to clean, it also helps to understand how each finish ages before choosing a surface.
Clay-based litter absorbs fresh, standing oil well, which makes later cleaning easier. It will not draw out oil that has soaked deep into old concrete.
Bleach does not dissolve oil, and it can discolor the surface and create hazards if mixed with other cleaners. Use a degreaser or detergent instead.
Water alone does not lift oil. Pressure washing after a degreaser can help rinse the slab, but keep the nozzle at a safe distance to avoid etching.
Oil deeper in the concrete can wick back to the surface as the slab dries. A repeat treatment, or a poultice, usually helps.
Describe the project and the surface you have now, and we will reply with what we need to know.