Learn How to Clean Concrete Stains

Step 1: Figuring Out the Concrete Stain Removal Type

You should treat stains differently depending on whether they're old or new. For older stains, skip to Step 2.

Porous concrete absorbs stains easily. If the surface was just stained, act quickly. Soak up as much as possible with paper towels. Don't rub the surface — it will drive the stain further into the concrete. Often you can remove a brand-new stain with only household cleaner and water. Use a nylon brush to scrub it away.

For large spills, apply spill absorbent to the area and let it sit for 24 hours. Then sweep it up the next day. If the stain is still there, follow the cleaning instructions in Step 2.

Step 2: Remove Any Dirt Debris

Thoroughly sweep or use a shop vacuum to remove any dirt or debris.

Step 3: Concrete Stain Removal By Stain Type

For best results, use a cleaner specifically tailored to your particular stain. Follow all cleaner instructions. With any cleaner, it's best to test in an inconspicuous area first. If that cleaner stains the concrete, try something else.

Grease or Oil
Soak up as much of the material as possible with a spill absorbent, then spray the stain with a degreaser. Allow the degreaser to saturate the stain for a few minutes and scrub or wipe away according to the manufacturer's instructions. Repeat if necessary.

Mastic
Residual mastic is often left behind on a concrete floor after you've pulled up tile or carpet. Use a putty knife and a stiff brush to scrape off as much as you can. To remove the remaining mastic, apply a citrus-based cleaner.

Paint
First, scrub the area with trisodium phosphate (TSP) and water. Rinse the area and allow it to dry a few hours, then scrape off peeling paint with a putty knife. Apply paint thinner and leave overnight. If it's a small stain, use a wire brush or scraper to remove the remaining paint. If it's in a large outdoor area, use a pressure washer. If the paint doesn't come off, add more thinner and repeat the steps.

Rust
You may be able to remove rust with household material such as lemon juice or vinegar. Pour it on the stain, let it sit for 10 minutes or so, and scrub with a wire brush. Rinse and repeat if necessary. For tougher stains, use a commercial cleaner according to the product instructions.

Step 4: What to Do After Concrete Stain Removal

After any of these stains have been removed, if you're cleaning a concrete floor, mop with water and floor cleaner. Use a shop vacuum to pick up any remaining water and debris. If you plan to seal or stain the floor after concrete stain removal, first let it dry for at least 24 hours. See How to Seal Concrete and Stain an Interior Concrete Floor for instructions.

If you're working on a large outdoor area, like a concrete driveway, clean the surface with a pressure washer. When working with a larger area, pressure cleaning concrete will take much less time than attempting to spot clean so you’ll really want to understand the mechanics of how to remove stains from concrete with a pressure washer when doing that. See Clean and Seal a Concrete Driveway to learn how.