Concrete Driveway Contractors in Boise, ID

It depends on what parks on it. A standard passenger-vehicle driveway is commonly four inches over a prepared base, and anything carrying an RV, a boat trailer or delivery vehicles is normally thicker with heavier reinforcement. Thickness gets set from the actual use rather than a default, because a slab poured too thin cracks under loads it was never sized for.

Concrete shrinks as it cures and moves with temperature, so it will crack. What good work controls is where. Control joints are cut at planned spacing so the slab relieves that stress along a straight line instead of across the middle. A driveway with no joints, or joints cut too late or too shallow, cracks wherever it likes.

Sometimes, and it is worth asking about because it saves demolition and haulage. It works where the existing slab is sound, drainage still works and the extra height does not create a problem at the garage door or the street. Where the old slab is moving or the base under it has failed, pouring over it inherits the problem.

For exterior concrete in this climate it is an important part of the specification. Air entrainment puts millions of microscopic bubbles through the mix, and those give water somewhere to expand into when it freezes instead of forcing the surface apart. It matters more on anything that gets de-icing salt, because salt increases the number of freeze-thaw cycles the surface goes through. It is not a guarantee on its own — mix design, water-cement ratio, curing, finishing and drainage all bear on how well concrete holds up.

They solve opposite problems. Control joints are cut or tooled into the slab to give shrinkage cracking a straight line to follow, so the slab cracks where it was planned to rather than across the middle. Expansion or isolation joints are gaps that let two separate elements move independently — a driveway against a garage slab, or a patio against the house foundation. A slab can be well jointed for shrinkage and still transmit movement into a building if the isolation joints were left out.

Foot traffic is usually a day or so and vehicles considerably longer, because concrete gains most of its strength over the first weeks rather than the first days. Exact timing depends on the mix, the thickness and the weather during curing, so it is given for your specific pour rather than as a general rule.