Cracks. The good, the bad and the … well, you know where this is going.
A Scottish friend of mine always asks, “What’s the crack?” to begin a conversation. Basically, a UK born way of saying, “Hey, what’s up?”. Well, it makes me laugh every time! So it has me thinking about cracks. Cracks in concrete. Ooooh! Fun, right? They are inevitable and you’ll find them in old homes and even in brand new homes and buildings that cost hundreds of millions to build.
Concrete is a great material but an imperfect one at times. It will crack eventually somewhere, somehow. For many reasons it may happen; too much water in the concrete mix, rapid curing, or improper strength for the job or even improper or NO expansion joints. Expansion joints can take the inevitable cracking and nicely say, “Crack – go here!”. That way, the unsightly random cracking in concrete will follow the pre-selected path and all becomes good in the world! I once had a contractor tell me that the slab around a pool didn’t need any saw-cut expansion joints and that it’d “mess up the look of the smooth concrete”. Well, as an architect, I wanted the visual interest of the scored pattern lines but I ALSO wanted the cracks that were going to arrive no matter how good the contractor thought his mixing and installation was going to be.
Most slab cracks aren’t structural and happen for the reasons above. It will be more an unsightly blemish than anything. However, when left unattended, they will allow water/freezing/heaving to occur and you’ll be looking at large removal and replace cost.
So when having your new driveway poured or your basement renovated – ask the contractor to add a few more expansion joint to allow the concrete to do what it’s going to do anyway. Take control of the cracks!
In this close-up of the picture above, notice the expansion joint has a crack exactly where we wanted it!