Concrete spalling or flaking is concrete that has broken, flaked apart or become pitted. Often, this condition is a result of the environment or a bad installation. Don’t be fooled, it can be so much more than just a cosmetic problem. For example, it can and most likely will grow and continue to deteriorate as it encounters rain, snow, and ice. Concrete spalling is more common in colder climates like Colorado, where the concrete endures freeze-thaw cycles. When concrete freezes, it expands just like ice, up to as much as 17%, creating pressure on the surrounding materials. Additionally, deicing chemicals will contribute to spalling and pitting. And once the spalling begins, it will continue to grow as more water will sit in the large holes and expand when frozen, causing it to flake and pit more and more. If you live in a colder climate, your concrete might already be exhibiting this type of damage, but it is even more so if the concrete was installed improperly. All of this applies to decorative concrete the same as broom finished flatwork, such as sidewalks and driveways.
To avoid future issues and save you time and money, it’s important to repair spalling at the first sign of pitting or flaking. To repair concrete spalling, the surface will need to be prepped. First, the damaged area will need to be removed, typically it will be chipped away or ground down. Second, clean the area thoroughly. An air compressor or another tool that shoots out controlled pressurized air is an excellent tool for this job.
The third step is to resurface the area using a polymer-modified cement compound. After the overlay dries, the fourth step is to seal the entire affected area with a waterproof sealer. A solvent based sealer will often last much longer than a water-based sealer. This process will help to prevent the spalling from occurring again.
As time passes, you will be able to tell if the sealer is still working, if droplets of water form on the surface and roll, like water on a car that has been waxed. If water is absorbed quickly into the concrete, it’s time to reseal.
By All About Home 1-30-2018