Sidewalks & Driveways

Almost always because of what is UNDERNEATH, not the concrete. If the base was not properly compacted, the ground gives way at one spot and concrete, which does not bend, breaks. The other reason is thickness: a walking sidewalk and a driveway a truck drives over do not call for the same thickness or the same reinforcement. That is why half the job is base prep and forming, before the mixer ever shows up.

Those are control joints. Concrete shrinks a little as it cures and it is going to crack no matter what: that cannot be prevented. What can be decided is WHERE. The joint is a deliberately weakened line so the crack shows up there, straight and hidden, instead of running across the middle. A sidewalk with no joints is not better: it is one that will crack wherever it feels like.

The main thing is the slope: no steeper than 1 in 12, meaning one inch of rise per foot of run. It also needs a flat landing top and bottom, the sides have to be handled so nobody walks off the edge, and it gets the yellow bumpy plate (the detectable warning) where the ramp meets the street. The city inspector checks it, and if the slope is off it has to be demolished and repoured.

Walking on it, next day. Driving a car onto it, not for about a week: concrete keeps gaining strength for days even though the top already looks hard and dry. Putting weight on it early is the easiest way to break in a new driveway with a crack. When we finish we give you the exact date based on the weather, because cold slows it down.