How to Clean and Prepare Concrete

Every concrete repair or restoration project starts with a thorough cleaning. Prepping the concrete surface before doing any restoration project is critical and can save you a lot of time and money.

If a concrete surface isn’t cleaned properly, any overlays, concrete levelling compound, or paints won’t grip and fuse to the existing concrete floor. This process is even more critical when it comes to acid staining concrete. If the floor isn’t cleaned properly, the stain won’t sink into the floor and react properly with the limestone, causing discoloration.  


How to Get Started Cleaning Concrete: Survey the Area

Before starting any job, stop and assess the area. Look for excessive laitance in the floor (weak layer of concrete and fines on the concrete surface). If there are any cracks or breaks in the concrete, all these will have to be fixed.

Make sure you know the precise specifications for your job at hand. Before starting any concrete restoration job, specifically overlays, there are certain things you need to know, and certain standards you should follow.

The Best Way to Clean a Concrete Surface

Begin by sweeping the floor to get rid of any dust and debris. Once swept up, use a biodegradable detergent as a concrete cleaner with a power washer and spray down the area. If your project area is indoors, use a mop and bucket with the biodegradable detergent to clean the area.

Once you’ve gone over the entire area, you may need to use a stiff bristled scrub brush (not a wire brush) to get out the more stubborn stains. If there’s excess water, use a wet/dry vac to remove it so the floor can dry.

For removing oil stains from concrete, you may have to use products like either hydrogen peroxide or ammonia and apply them directly to the oil spots. With a little scrubbing, you should be able to get the concrete clean. TSP is another product that can be used as a concrete oil stain remover.

Once the floor is dry, if the area still isn’t as clean as it needs to be, try using TSP, which should get the floor clean enough to prep for either painting or overlays. When it comes to stain removal, always start with the least toxic cleaner and up your game when needed.

How to Clean and Prepare Concrete For Staining

Unlike overlays or paints, staining, either with acid stains or water-based stains, requires the area to be completely clean and free of any impurities in or on the concrete that will affect the end result of the staining processes.

For surface contaminants, such as paint, you need a stiff brush and a chemical remover, such as paint thinner, to remove the imperfections. Once the surface of the concrete is clean of the contaminant, use a palm sander to clean the pores of the concrete where the stubborn stains were.

Once you feel that the area is cleaned, wet the infected area. You’ll know when the area is clean enough when the stain doesn’t appear on the wet concrete. For more information on how to clean concrete and properly prepare your concrete surface, feel free to check out //

So there you have it. That’s how we recommend cleaning your concrete patio, concrete driveway or basement foundation before starting a concrete restoration, rejuvenation or repair project.