How to Clean Black Fire Residue from a Concrete Driveway

Soot, or carbon based stains are especially difficult to remove from most surfaces, including concrete.  While you’d normally first attack this type of stain with a chemical sponge, the rough surface of a concrete driveway may make that an impractical chore.  Instead, try this method using an alkaline concrete degreaser designed to cut through tough soot.

• Krud Kutter or another alkaline degreaser
• Push broom with short, stiff bristles
• Bucket
• Running water
• Protective gear (as indicated on the product label)

1. Sweep the surface to free it of loose debris.
2. Dilute the cleaner to the desired strength according to the label directions. Soot removal may require a full strength application, depending on the product and specifications.
3. Apply the mixture to the concrete as directed. In the case of a flat or gently sloped driveway, you may be able to simply pour the solution on the concrete.
4. Use the broom to agitate the solution against the surface. Use short, brisk strokes for maximum penetration into the stain.
5. Allow the product to remain on the driveway for the specified period of time.
6. Rinse thoroughly with clean water.
7. Repeat if necessary until all of the soot is removed.

• Soy Fast Degreaser is also environmentally safe and may be washed away. If you use another product, be sure to choose an alkaline degreaser that’s safe for concrete and safe to wash off outside, and follow all product label guidelines and instructions.
• Before you begin, be sure to gather and use any suggested protective gear, including eye protection.
• One of the biggest reasons degreasers fail to work is not having enough contact time with the surface to be cleaned. While soot may take more than one application under the best of circumstances, it’s especially important that you allow the cleaner time to work into the stain before rinsing it away.
• Follow up with a good rinse from a pressure washer if desired.