How Are Surfaces Prepared for the Application of Concrete Overlays?

Preparing for a Concrete Overlay

Preparing for a Concrete Overlay

If you are interested in having a concrete overlay applied to an indoor or outdoor surface at your home, there are two critical factors. First, you need to choose a top product, something like SunStone, Tuscan, or SunSamp. Second, to enjoy the beauty and functionality of the overlay, surface preparation is imperative. Otherwise, even the best concrete overlays will not adhere properly.

When looking at the different steps involved with laying concrete overlays, proper surface preparation is by far the most critical. In the past, installers relied on power washing, acid etching, or chemical cleaners to grind the surface down. Today, reputable professionals also can use diamond pads or diamond cup wheels. What it comes down to is that the surface must be thoroughly prepared, which still involves power washing in some cases.

Before placing concrete overlays, an installer will look for any obvious grease spots, paint stains, oil slicks, or anything else that would prevent firm overlay adhesion. Known as “bond breakers,” these substances are removed using a chemical or mechanical solution. While chemicals strip these elements off without profiling the surface, mechanical methods involve things like bead blasting and grinding.

In addition to visible bond breakers, installers perform a quick and easy water test to identify anything not seen by the naked eye. This test involves pouring a small amount of water on the surface and then watching for the formation of beads or standing water. Both of these indicate the existence of invisible bond breakers. Again, a chemical or mechanical process is used to eliminate the substances.

As part of preparing the surface for concrete overlays, the best installers also pay close attention to moisture control. If moisture is emitting through the surface, the concrete may ultimately fail. Also, any imperfections are corrected, including pits, cracks, spalling, and so on. The goal is to end up with a surface that is level, clean, and void of imperfections so that the overlay adheres perfectly.

If you are interested in having a decorative overlay applied to an indoor or outdoor surface as part of new construction, it is common for installers to place a rough base slab of concrete so that they do not have to worry about protecting the surface during build-out. After the general construction phase is complete, the installer can then start on the detail work by applying concrete overlays to create the finished decorative surface as requested by the homeowner.