Concrete patio cost

A concrete patio costs $8 to $26 a square foot installed, typically around $14. A 300 square foot patio is therefore $2,400 to $7,800. Plain broom-finished concrete is at the bottom; stamped and colored concrete is at the top.

It is the cheapest hard surface per square foot and the one where the base under it decides whether it lasts twenty years or cracks in three.

What it costs

The base is the whole thing

Concrete does not fail because the concrete was bad. It fails because what it was poured on moved.

A correct patio has 4 to 6 inches of compacted gravel over undisturbed or properly compacted subgrade, graded to drain away from the house at about a quarter inch per foot. The slab is 4 inches thick with mesh or fiber, thicker if anything heavy will sit on it.

What goes wrong:

No base, or an uncompacted one. The slab settles unevenly and cracks.

Poured on topsoil or fill. Organic material decomposes and the ground under the slab disappears.

No drainage fall, so water sits on it and against the house.

Poured too thin or with no reinforcement.

No control joints, or joints cut too late or too shallow. Concrete cracks; joints decide where. Joints should be about a quarter of the slab depth and no more than 8 to 10 feet apart.

Ask what the base preparation is and what the slab thickness will be. A contractor who answers immediately is the one you want.

Concrete will crack

This is worth accepting before the job rather than discovering after.

Concrete shrinks as it cures and moves with temperature. Every slab develops cracks. Control joints are there so the cracks happen along a straight tooled line where nobody minds them.

What is not normal: cracks wider than about an eighth of an inch, cracks where one side is higher than the other, cracks that run diagonally across a joint, and any crack that appears within days.

Stamped concrete, honestly

Stamped concrete is pressed with a texture mat while wet and colored, to look like stone or brick. At $15 to $26 a square foot it competes with pavers.

The case for it: it is a single monolithic surface with no joints for weeds, and the pattern options are unlimited.

The case against: the color is on or near the surface, so a chip shows gray concrete. It needs resealing every two to three years at $0.50 to $2 a square foot, and it becomes slippery when the sealer builds up. A crack across a stamped pattern is far more visible than a crack in a plain slab, and it cannot be repaired invisibly.

Pavers cost about the same, can be lifted and reset if the ground moves, and individual units can be replaced. For a patio in a freeze-thaw climate, that flexibility is worth real money.

Frequently asked questions

How long does a concrete patio last?

Thirty to fifty years on a proper base. The finish ages faster: a sealed decorative surface wants resealing every two to three years, and a plain broom finish wants nothing.

Can I pour concrete over an existing slab?

An overlay of a half inch to two inches over a sound slab is possible and it is a resurfacing product rather than new concrete. Over a cracked or moving slab, the crack comes through the overlay within a season.

When can I use it?

Walk on it after 24 to 48 hours, furniture after a week, vehicles after 28 days. It reaches most of its strength in the first week and continues curing for a month.

Should I seal it?

Decorative finishes, yes, on the manufacturer's cycle. Plain concrete, optional: a penetrating sealer reduces staining and freeze-thaw damage and costs $0.50 to $2 a square foot. In a cold climate it is worth doing.

What is the cheapest patio?

Gravel at $2 to $6 a square foot, then plain concrete at $8 to $14. Below that the options are not really patios. Concrete is the cheapest hard, level, furniture-friendly surface.