Hugh Cairns: Concrete driveway spalling

De-icing chemicals aggravate spalling concrete by allowing more water to migrate into the concrete increasing the size and depth of the spalling failures when a freeze/thaw cycle occurs. That’s why spalling problems are often associated with vehicle storage.(Photo: Hugh Cairns)

All about – Concrete driveway spalling

Spalling on concrete driveways is easy to spot once it is underway. Rough, pitted or flaky areas in the driveway indicate spalling. Concrete driveway spalling is usually a result of installation, environmental and mechanical factors. Most cases start off as cosmetic in nature affecting the surface of the concrete driveway only. Spalling can penetrate much deeper damaging rebar, for this reason it is important to get on it and nip it in the bud.

It stands to reason that the best time to address concrete spalling is before it starts. Using the correct concrete mixture and proper curing techniques is a must. There are a host of sealants available that prevent spalling that can be applied upfront. Sealants are available that are decorative in nature.

Concrete flaking and scaling can be caused during the freeze thaw process in the winter. Moisture in the concrete can freeze and cause the material to expand which creates pressure. Repetition of this cycle can cause the surface to scale or flake. Applying de-icing products on concrete can accelerate the spalling by introducing more moisture into it. Your vehicle can bring home de-icing compounds and deposit them right on your driveway with you thinking about it. That’s why spalling problems are often associated with vehicle storage.

Spalling conditions can be caused during the driveway installation. In this case the top layer of concrete may have cured faster than the material below it causing moisture to be trapped. This causes a weak layer between the surface and the stronger slab below. 

If you notice concrete spalling it’s best to act quickly and address it. The longer you leave the surface to deteriorate the higher the risk of more serious damage. Most of us aren’t versed in repairing concrete spalling. In this case I recommend that you bring in the right pro, with the right experience and the right tools. In situations like this, by the time you figure out and gather all the tools and materials the project would most likely be finished by a pro.