We have all seen them and just about every garage has them...cracks! With concrete, it's not a matter of "if" it will crack, it's a matter of "when" it will crack. Fortunately, it is still warm enough to do something about these cracks before they lead to bigger issues. When the concrete in your garage cracks it presents an entry point for water to get down below the slab. Snow melt from cars is the leading contributor of excess water. Water will cause the substrate (fill) below the slab to settle which can lead to differential settling between the cracked pieces of concrete. Water can also lead to heaving of the garage floor which can get a little ridiculous depending on the type of soil below your slab. If there is high clay content in the substrate it can expand quite a bit especially near the door if it freezes. I have seen slabs that have raised 2 to 3 inches when frozen. This not only is an issue with drainage on the garage floor but it can cause a crown in the floor which leaves a gap at each end of the garage door when closed. Snow and pests can make their way in through this opening.
To keep small cracks small it doesn't take too much DIY effort. The goal is to keep the water from running through the cracks. First step: Cleaning the cracks out with a pick and vacuum, this will help the crack sealant stick to the concrete. Second step: Apply a self-leveling polyurethane sealant. It is easy to use and doesn't require additional smoothing of the sealant. Due to the temperature changes that a garage slab is exposed to it is best to use a sealant that retains some flexibility. That's it, scratch another project off the honey-do list. Until next time...