Concrete patio installation starts with the ground, not the concrete

Laying concrete for a patio means preparing the soil first, building a frame, pouring the mix, and finishing the surface. Most of the work happens before concrete touches the ground. The soil must be compacted, the frame must be level, and the concrete must be the right thickness — usually 4 inches for a patio that will hold foot traffic and light furniture. If you skip preparation, the concrete will crack, settle unevenly, or both.

This is a project you can do yourself if you have a few days, basic tools, and help for the heavy lifting. Renting a concrete mixer and a plate compactor will cost less than hiring a contractor for a small patio, though large patios (over 200 square feet) often make more sense to hire out because the concrete sets quickly and mistakes are hard to fix once it hardens.

Key Takeaways

  • The ground must be compacted to 4 to 6 inches deep, sloped slightly for water drainage, and cleared of grass, roots, and debris before you build the frame.
  • The frame (usually 2-by-4 lumber) must be level and square, held in place with stakes, because the concrete will follow the frame's shape and slope.
  • Concrete should be 4 inches thick for a patio, mixed to a consistency that holds together but is not soupy, and poured in one session if possible to avoid weak seams.
  • The surface is finished by screeding (striking off excess concrete), floating (smoothing), and broom-finishing (adding texture for grip) while the concrete is still wet.
  • Concrete takes 24 to 48 hours to harden enough to walk on, and 28 days to reach full strength before you move heavy furniture onto it.

Prepare the ground and check the slope

Mark out the patio area with chalk or string. Dig out the top 4 to 6 inches of soil, removing grass, roots, and rocks. The ground should slope away from your house or any structure at a rate of about 1/8 inch per foot — this prevents water from pooling. You can check this with a long level and a tape measure: place the level on a straight board across the area, and measure the height difference at each end.

Once the soil is dug out, compact it firmly using a plate compactor (rent one from a tool rental shop for about $40 to $60 per day). Make multiple passes over the entire area. Loose soil will settle under the weight of the concrete and cause the patio to crack or sink. If the soil is very dry, lightly water it before compacting — damp soil compacts better than bone-dry soil.

Build and level the frame

Use 2-by-4 lumber to build a frame around the patio area. Cut the boards to length and lay them on edge along the perimeter. The inside of the frame is where the concrete will go. find the frame with 3-inch deck screws or nails, driving them through the boards into corner blocks or into each other at the corners.

Drive wooden stakes into the ground on the outside of the frame, spaced about 4 feet apart, and screw or nail the frame to the stakes. Use a long level (4 feet or longer) to check that the frame is level side to side and slopes correctly front to back. Adjust the stakes by tapping them deeper or pulling them up until the frame is true. This step takes time but is worth it — the concrete surface will be only as level as the frame.

Mix and pour the concrete

Calculate the volume of concrete you need by multiplying length × width × depth (in feet) and dividing by 27 to get cubic yards. A 10-by-12-foot patio at 4 inches deep needs about 1.5 cubic yards. You can order ready-mix concrete delivered by truck, or rent a mixer and buy bags of concrete mix. For small patios (under 100 square feet), bags are cheaper; for larger ones, ready-mix is faster and easier.

If using a mixer, follow the bag instructions for water ratios. The concrete should be thick enough to hold its shape but wet enough to work — think of thick cake batter. Pour the concrete into the frame and spread it roughly with a shovel. Work quickly because concrete begins to set within an hour or two, depending on temperature and humidity. On hot days, work faster. On cool days, you have more time.

Strike off excess and float the surface

Once the frame is full, use a straight board (a 2-by-4 works well) to screed the concrete. Place the board across the top of the frame and drag it toward you in a sawing motion, removing excess concrete and filling low spots. Make multiple passes until the surface is level with the frame. This step is called screeding.

After screeding, use a float — a flat tool with a handle — to smooth the surface. Push the float across the concrete in overlapping strokes, working out air pockets and creating a more finished look. Floating also brings a thin layer of cement paste to the surface, which hardens to a durable finish. Do not over-float; stop when the surface looks smooth and the aggregate (gravel) is mostly hidden.

Add texture and let it cure

For safety, add texture to the surface so it is not slippery when wet. The easiest method is broom-finishing: drag a stiff broom across the concrete in straight lines or a pattern. Do this while the concrete is still damp but firm enough that the broom does not sink in. Test a small area first. If the concrete is too wet, wait a few minutes; if it is too hard, you have missed the window.

Once finished, cover the patio with plastic sheeting or burlap to slow evaporation and help the concrete cure evenly. Keep it moist for the first 24 to 48 hours by misting it with water or leaving the covering on. The concrete will be hard enough to walk on after 24 hours but will not reach full strength for 28 days. Do not move heavy furniture or park vehicles on it until then.

Common mistakes and how to avoid them

Uneven ground is the most common problem. If you do not compact the soil or level the frame carefully, the concrete will settle unevenly and crack. Spend extra time on this step. The second mistake is pouring concrete in sections on different days. Concrete poured at different times creates weak seams where the old concrete meets the new. If you must pour in sections, use a bonding agent on the edge of the old concrete before pouring the new.

Finishing too early or too late is also common. If you float or broom the surface when the concrete is too wet, you will bring up too much paste and the surface will be weak. If you wait too long, the concrete will be too hard to work. Watch the concrete as it sets and test it by pressing your finger into it — when your finger leaves a mark about 1/4 inch deep, the timing is right for finishing.

Frequently Asked Questions

How much does concrete cost for a patio?

Ready-mix concrete costs about $150 to $200 per cubic yard delivered, though prices vary by region and supplier. A 10-by-12-foot patio at 4 inches deep needs roughly 1.5 cubic yards, so material alone runs $225 to $300. Bagged concrete is more expensive per cubic yard but has no delivery fee, making it cheaper for very small patios under 50 square feet.

Can I pour concrete in cold weather?

Concrete sets more slowly in cold weather and can be damaged by freezing before it hardens. Avoid pouring when the temperature is below 50 degrees Fahrenheit or will drop below freezing within 24 hours. In cold climates, spring and fall are better times than winter. If you must pour in cool weather, use concrete mix designed for cold weather and keep the finished patio covered and moist for longer than usual.

What if I want a decorative finish instead of broom texture?

You can stamp patterns into concrete while it is still wet, stain it with concrete dye, or expose the aggregate by washing away the top layer before it fully hardens. These techniques require practice and special tools. For a first project, broom finish is the most forgiving and still looks clean and professional.

How do I fix cracks that appear later?

Small cracks (hairline width) are normal as concrete cures and are usually not a problem. Wider cracks can be filled with concrete crack filler or caulk. For large cracks or settling, the damage usually points to poor ground preparation — the concrete may need to be removed and re-poured if the problem is severe.

Do I need a permit to pour a patio?

Most cities do not require a permit for a straightforward patio, but some do, especially if it is large or close to property lines. Check with your local building department before you start. A permit is inexpensive (usually under $50) and takes a few days to get, but skipping it can cause problems if you sell the house or need to file an insurance claim later.