Concrete Surface Preparation

Concrete surface preparation is the most important part of any decorative concrete flooring project. For the project to hold up over time, you must begin with a surface that is clean, dry and sound. Unless you are starting with a brand new concrete slab, this often means beginning by removing the adhesive, carpet glue, or paint, and sometimes a combination of these three residues.

How a surface is prepared for one of our EcoCrete Overlays:

1. Clean: Yellow adhesive, water-based and is common today with vinyl tile and carpet. The most predictable and efficient method of removing these adhesives is concrete grinding.
   Chemical strippers are effective in removing this layers of paint and sealer, as well as excessively sticky adhesives that would clog grinders. But their residue can permanently stain the concrete, so a sample area should be done first. Paint overspray, drywall mud, and other stains or markings can usually be removed with a rotary floor scrubber, or a grinder fitted with a sanding disc.
2. Dry: Once the surface is clean, it should be tested for moisture content and moisture vapor transmission. Excess water in concrete can cause problems with stain color and with the adhesion and clarity of concrete sealers. Because there are a variety of testing methods for moisture in concrete and some require special equipment and training, this is best left to a contractor or professional. If moisture is determined to be a problem, and does not have an identifiable cause that may be fixed, dehumidification equipment often helps to dry the concrete to acceptable levels. New concrete requires at least 28 days to cure, and usually about 3 months for excess moisture from the concrete mix to evaporate. We test concrete slabs for moisture at the time of the pre-project onsite consultation to ensure that the concrete is dry enough to stain and seal.
3. Sound: lastly, concrete surface preparation may require patching holes and repairing cracks. Patching can be done effectively with most cement grouts and mortars. Patches, however, do not always blend in color with the rest of the floor, and they do not always accept concrete stain in the same manner as the concrete. If the repairs are small and few in number, they may not stand out, or artists' tints and faux finishing techniques may be used to disguise them. Even if they do stand out, such as large patching from plumbing repairs or upgrades, the look is usually acceptable. But to remove all signs of patching, a concrete overlay is usually required, and a concrete overlay is always required to remove all signs of crack repairs.

Regardless, cracks almost always add to the look of stained concrete by providing a more natural stone appearance. Many customers actually want cracks with their stained concrete.

Once the concrete is clean, dry, and sound, the basis has been established for a successful decorative concrete project that will last for years to come. We use a well-informed, comprehensive approach to preparing a concrete slab for staining, including all the above methods, and using the best and latest technology.