Building a concrete patio takes four to six weeks from start to finish, including curing time

A concrete patio begins with site preparation—clearing the ground, leveling it, and building a frame—then pouring concrete into that frame and finishing the surface. The actual pouring takes a few hours, but the concrete needs seven days before you can walk on it and 28 days before it reaches full strength. The work is physical but straightforward: you dig, build forms, mix or order concrete, pour it, smooth it, and wait. Most homeowners can handle a small patio (8 by 10 feet or smaller) without hiring a contractor, though larger projects benefit from renting a concrete mixer or ordering ready-mix concrete delivered by truck.

Key Takeaways

  • Concrete patio work happens in stages: site prep, building wooden forms, pouring concrete, finishing the surface, and curing for at least seven days before use.
  • You will need a level, a shovel, a wheelbarrow, wooden boards for forms, concrete (either bagged and mixed by hand or ready-mix delivered), and finishing tools like a trowel and broom.
  • The ground must slope slightly away from your house—about one-eighth inch per foot—so water drains and does not pool against the foundation.
  • Concrete reaches walking strength in seven days but full strength in 28 days; do not place heavy furniture or vehicles on it before that time.

Measure the space and mark out the patio area

Start by deciding the size and location of your patio. Mark the corners with stakes and string to outline the exact footprint. Use a tape measure to verify the dimensions and a carpenter's square to check that corners are at right angles. If the patio will be against your house, measure out from the house wall at multiple points to make sure the edge runs parallel.

Check the ground for obstacles—tree roots, rocks, utility lines. Call 811 before you dig if you are not certain where underground gas, electric, or water lines run. This is a free service in most areas and takes a few days, but hitting a line can be dangerous and expensive.

Prepare the ground and build the forms

Remove grass, weeds, and the top 4 to 6 inches of soil from the marked area. Use a shovel to dig out the space, working in sections. Compact the soil as you go by tamping it down with the back of a shovel or a hand tamper. The ground should be firm and level, with no soft spots or standing water.

Build a frame (called forms) from 2-by-4 lumber around the perimeter of the patio. Nail or screw the boards together at the corners, and stake them to the ground with wooden stakes driven in from the outside. The top of the forms should be level and at the height you want the finished patio to be. Slope the forms very slightly—about one-eighth inch per foot—away from your house so water runs off and does not collect against the foundation. Use a level to check this slope as you build.

Order or prepare concrete

For a patio smaller than 100 square feet, you can mix bagged concrete by hand. Bags typically contain 60 or 80 pounds and mix with water in a wheelbarrow or concrete mixer. Follow the bag instructions for water ratios—too much water weakens the concrete, and too little makes it hard to work with.

For larger patios, order ready-mix concrete delivered by truck. Call a local concrete supplier and tell them the square footage and thickness (usually 4 inches). They will deliver concrete in a truck and pour it directly into your forms. Ready-mix is faster and stronger than hand-mixed bags, but you need to be ready to work when ready when the truck arrives—concrete begins to set within a couple of hours. Have helpers on hand and all your finishing tools ready before the truck shows up.

Pour the concrete and level it

Spread the concrete evenly across the forms, working it into corners and against the edges. Use a shovel to move concrete around, then drag a straight board (called a screed board) across the top of the forms to level it. The screed board should be longer than the patio is wide; rest it on top of the forms on both sides and drag it toward you in a sawing motion, filling low spots as you go.

Work in sections if the patio is large. Pour one section, screed it level, then move to the next. Tap the sides of the forms with a rubber mallet as you work to help concrete settle and remove air pockets. The surface should be roughly level and flush with the top of the forms when you are done screeding.

Finish the surface

Once the concrete is screeded level, let it sit for 15 to 30 minutes so excess water rises to the surface. Then smooth it with a float—a flat tool that you push across the surface in overlapping strokes. Floating closes small holes and creates a smoother finish. Work in sections, floating one area, then moving to the next.

For a non-slip surface, drag a stiff broom across the concrete after floating. This creates a textured finish that is safer when wet. Broom the surface in one direction for a consistent look. If you want a smoother finish, skip the broom and float the surface again after it has firmed up a bit more.

You can also add a bevel to the edges—a slight angle that prevents chipping. Run a bevel tool along the edges where the concrete meets the forms, or straightforward round the edges with a trowel.

Remove forms and cure the concrete

After the concrete has set for 24 to 48 hours, remove the wooden forms by unbolting or unscrewing them from the stakes. The concrete will be hard enough to handle this, though it is still curing. Backfill the gaps left by the forms with soil.

Keep foot traffic off the patio for at least seven days. The concrete reaches walking strength in that time, but it continues to cure for 28 days. Do not place heavy furniture, vehicles, or equipment on the patio for the full 28 days. If it rains during the first week, cover the patio with plastic sheeting to slow evaporation and prevent surface damage.

Common mistakes to avoid

Not sloping the ground away from the house causes water to pool against your foundation, leading to cracks and leaks. Check the slope with a level before you pour. Mixing concrete with too much water weakens it and causes surface scaling (flaking) later. Follow the bag or supplier instructions exactly for water ratios.

Pouring concrete in direct sun or high heat causes it to cure too fast and crack. If the weather is hot, wet the ground before pouring and cover the finished patio with plastic or burlap to slow evaporation. Cold weather below 50 degrees Fahrenheit also causes problems—concrete cures very slowly and may not reach full strength. Plan patio work for spring or fall when temperatures are moderate.

Walking on the patio too soon is tempting but weakens it. Seven days is the minimum; 28 days is better. Removing forms too early can cause the edges to crumble. Wait at least 24 hours, and 48 is safer.

Frequently Asked Questions

Can I pour concrete on top of old concrete?

Yes, but the old concrete must be clean and slightly roughed up so the new concrete bonds to it. Pressure wash the old surface, let it dry, then explore a concrete bonding agent before pouring. If the old concrete is cracked or uneven, fill large cracks and grind down high spots first.

What thickness should a patio be?

Four inches is standard for residential patios. This thickness handles foot traffic and light furniture. If you plan to park a vehicle on the patio, use 5 or 6 inches instead. Thicker concrete costs more but lasts longer under heavy use.

Do I need to add rebar or wire mesh to the concrete?

For a small residential patio, it is not required, but it does reduce cracking. If you use reinforcement, lay it in the middle of the concrete thickness—not on the ground or at the surface. Wire mesh is easier to handle than rebar for a DIY project.

What should I do if concrete cracks after it cures?

Small hairline cracks are normal and do not affect the patio's strength. Seal them with concrete crack filler to prevent water from entering. Larger cracks (wider than one-quarter inch) may indicate a problem with the base or slope; consider having a contractor inspect it.

How do I keep the patio clean?

Sweep it regularly to remove dirt and debris. Pressure wash it once or twice a year to remove algae and stains. Seal the concrete every two to three years with a concrete sealer to protect it from water, salt, and UV damage.