By Emily Newton

Concrete floors are popular choices as they are extremely durable and long-lasting if installed, cured, and finished properly. However, issues can arise during or after installation, and construction professionals must know how to diagnose and fix these concrete flooring challenges.

This article outlines some crucial steps to take when addressing challenges in slab-on-grade concrete floors, including those with polished or broom finishes. Although most relate to concrete floors installed indoors—in residential and commercial buildings—some tips also apply to those installed outdoors.

Determining the issues and causes

A good start in the troubleshooting process is to ask the clients when the issues started and if any activities caused them to worsen over time. Sometimes, environmental factors can exacerbate problems, for example, products for cleaning and deicing can harm the concrete, as can frequent traffic from heavy vehicles such as forklifts. If the concrete flooring is in a protected area, such as a garage, be aware of how people can track products such as deicing salts onto it by walking.

Clients may also need help because they noticed specific areas where the concrete floor has started to bulge. This issue generally occurs because of soil upheaval following heavy rainstorms—water builds under the concrete and pushes it up. Problems can also occur if the floor is exposed to freezing temperatures soon after installation.

Cracks are other common concrete flooring challenges. They could occur after a sudden impact, for example, if a heavy object is dropped onto the floor. In this case, the client can confirm exactly when and why the crack happened. However, it becomes more complicated if the cracks appear because of installation mistakes. For example, the installer may use too much water in the mix or select the wrong strength of concrete to pour.

Concrete slab design can include reinforcement to compensate for shrinkage, decreasing the possibility of cracking.¹ Most cracks arise due to issues associated with how well the floor cured. Although the first few days are critical, concrete does not reach its full strength until at least 56 days after installation.