What are the downsides of having a concrete driveway?

What goes wrong with a concrete driveway?

All concrete cracks. It shrinks as it dries and moves with the ground, so the question is where. Control joints cut into the slab give the cracks a straight line to follow. Without them, or with joints too far apart, cracks wander across the driveway.

The surface can be damaged in winter. Salt and freeze-thaw cycles can flake the top layer, called scaling, especially in the first winter. Oil and rust stains soak in unless the slab is sealed. Repairs never quite match the colour of the old concrete, and a new driveway needs about a week before you drive on it.

The biggest downside is the upfront cost. Concrete costs more to put down than asphalt or gravel. What you get back is a longer life and less upkeep.

How thick should a concrete slab be for a driveway?

Commonly cited general practice is 100 mm (4 in.) for cars, and 125 to 150 mm (5 to 6 in.) for heavy pickups, RVs or work trucks. It sits on a compacted crushed-gravel base, often 100 to 150 mm (4 to 6 in.) deep.

Your soil, what you park and the City's standards at the street set the real spec. A thin slab on a weak base is the most common reason a driveway cracks and sinks early.

Can I pour concrete directly on dirt?

For a driveway, no. Topsoil and organic material compress and hold water, so the slab settles unevenly and cracks. The usual approach is to dig down to firm subgrade, then build up a compacted gravel base that drains and gives the slab an even bed.

The same goes for grass. Pouring over turf traps organic material that rots under the slab and leaves voids.

Is painting a concrete driveway a good idea?

Usually not. Paint sits on the surface, and tires, salt and water wear it off in patches. Once it peels, it's harder to fix than the bare concrete was.

If you want colour, it works better in the concrete itself, as integral colour or a stain, or in a stamped finish. A penetrating sealer protects the surface without peeling.

What is a cheap alternative to concrete?

Gravel is the cheapest to put in. Compacted road base, sometimes called poor man's concrete, packs harder than loose driveway gravel but still ruts and needs topping up. Asphalt costs less than concrete up front and is quick to drive on.

Pavers are another option. They cost more to install than plain concrete, but single units can be lifted and reset. Each one lasts as long as the base under it.

What are the pros and cons of asphalt vs. concrete driveways in Canada?

Asphalt usually costs less to put down and flexes a little with frost. It needs sealing every few years, softens on hot days and tends to wear out sooner. Concrete costs more up front, lasts longer, handles heat better and gives you finish options. Salt in the first winter is its weak spot.

In both cases the base underneath decides most of the driveway's life. Send a photo of your driveway with the booking form and John will tell you what a concrete one would need.

The bottom line

A concrete driveway costs more to put in than asphalt or gravel, it will crack somewhere, and de-icing salt and oil can mark the surface. A good base, the right thickness, control joints and sealing handle most of these, which is why concrete usually outlasts the alternatives.