Should we tie the apron rebar into the shop floor?

… or the driveway into the garage floor?

The short answer is no. And this photo is why.

This was taken in February, the second winter this apron was in. It was poured a half inch lower than the shop floor.. but with the frost coming in and out, it’s pushed it up almost 2 inches! When the frost comes out, it will go back down to the original height. 

Frost and nature is a powerful thing and there’s no use fighting it for something like a concrete apron or driveway! We just let the frost do it’s thing with the apron and typically, the heat from the shop or garage keeps the frost out from under the concrete floor, so it stays as is!

Drainage under the concrete apron or driveway slab is critical.. but not always possible. We use expansion material in between the floor and apron to break the bond so as they shift, they don’t apply pressure to each other. 

If you dowel the rebar into the threshold, the frost will lift the apron and rebar and the threshold will go with it. There is the option of putting in void form or screw piles if really necessary but these options will almost double the cost.

So for the average concrete driveway or shop apron, we recommend just letting it float!