How to Clean Concrete Surfaces Before Sealing

Tips on Properly Cleaning Concrete Surfaces Prior to Sealing

Almost every home has at least some concrete surfaces, whether they are exposed foundation, patios, walkways, porches, garage floors, decorative pieces, concrete countertops, or any number of other possible options.

Regardless of what type of concrete you have, it can eventually deteriorate due to weather, use or time. Concrete is particularly vulnerable to moisture, which can cause it to slowly erode, creating an eyesore that eventually causes the structure to lose its integrity.

However, a simple coat of sealer can protect concrete for many years, while simultaneously providing a hard top layer and even decorative qualities. Sealers create a watertight barrier on the surface of the concrete, which can keep away any number of foreign substances. Concrete is a naturally absorbent material which makes proper sealing particularly important for areas prone to spills, such as garages and countertops. Here are a few tips on properly cleaning concrete surfaces prior to sealing to ensure the best possible protection.

Properly prepare surfaces prior to sealing
It is extremely important that you start with the cleanest surface possible prior to sealing concrete. This ensures that you do not trap any corrosive substances into the material, as well ensures a much nicer final product. First, try to remove any noticeable stains. For wet stains from oil or grease, try putting down an absorbent powder material, such as cat litter, saw dust or talc for a few days, then sweeping it up. This should soak up a large amount of residue. For dried stains or other types of discoloration from rust, mold, tire marks, or weathering, try diluted bleach or other household cleaners for especially stubborn stains.

Once you have removed stains, it is time to prepare the entire surface. Use a brush or broom to remove any dust and dirt that may have accumulated. Then wash the entire surface area. For a large section, such as a garage floor or patio, you may want use a mop to cover the surface with mild soap diluted in warm water.  Leave the mild solution for about 10 to 30 minutes, then pressure wash the area to remove both the soap and the dirty water. For smaller pieces, you can use a warm washcloth with mild soap to wipe it off, and then clean with plain water to remove all remaining soap and dirt.

Treating tough stains
If you find that water and household cleaners are not getting the surface as clean as you would wish, you may want to look into a cleaner made specifically for concrete. This is particularly true if the concrete has a rough surface, such as a broomed finish or exposed aggregate. These can be very difficult to clean and will most likely require more attention and time than flat surfaces.

Be extremely careful if your concrete has decorative elements, such as inlaid tiles or delicate aggregates, including minerals, glass or metals. These may be harmed by some household or specialized cleaners. Read all instructions first, and if in doubt, use a gentler cleaner or test the product on a small, relatively unnoticeable area. Most cleaning products and techniques will result in some lightening of the concrete surface color, thus, it is important that you remain consistent across the entire surface.