Pouring a cement patio is a weekend project that requires careful preparation, the right tools, and patience while the concrete sets
A cement patio starts with a level subbase, a wooden frame (called formwork), and concrete mixed to the right consistency. You pour the concrete into the frame, level it, finish the surface, and let it cure for at least seven days before walking on it. The entire process—from digging to a finished patio you can use—takes about two weeks, though most of that is waiting time.
This guide walks you through each step in order, with the timing and common mistakes that slow down first-time builders. The work is physical but not technical; the main skill is keeping everything level and not rushing the curing time.
Key Takeaways
- The subbase must be compacted and level to within one-quarter inch across the entire patio, or the finished concrete will crack and settle unevenly.
- Wooden formwork (usually 2-by-4 boards) holds the concrete in place while it sets and must be staked firmly so it does not bow outward.
- Concrete should slope slightly away from your house—about one-eighth inch per foot—so water drains and does not pool against the foundation.
- Concrete takes seven days to cure enough to walk on, but reaches full strength after 28 days; covering it with plastic during this time protects it from rain and speeds curing.
- A power mixer or ready-mix delivery saves hours of hand-mixing and produces more consistent concrete than mixing in a wheelbarrow.
Measure the area and mark out the patio boundaries
Start by deciding the size and shape of your patio. Mark the corners with wooden stakes and run string between them so you can see the outline on the ground. Measure diagonally from corner to corner—if both diagonals are equal, your rectangle is square. For an irregular shape, mark the perimeter with spray paint or chalk.
Check that the ground slopes away from your house. Use a long level (4 feet or longer) and a tape measure: place the level on the ground pointing away from the house, and measure the height difference between the end closest to the house and the end farthest away. You want about one-eighth inch of drop per foot of distance. If the ground slopes toward your house, you will need to regrade it or accept water pooling against the foundation.
Dig out and compact the subbase
Remove grass, roots, and topsoil from inside the marked area to a depth of 4 to 6 inches. A shovel works for small patios; a rented sod cutter or small excavator saves time for anything larger than 100 square feet. Dig out any soft spots or clay that holds water, because concrete poured over wet or unstable ground will crack and settle.
Spread 4 inches of gravel or crushed stone over the dug-out area and compact it firmly with a hand tamper or rented plate compactor. The subbase must be solid and level—walk across it and listen for hollow sounds, which mean soft spots underneath. Compact those areas again. A weak subbase is the most common reason patios crack within the first year.
Build and level the wooden formwork
Cut 2-by-4 boards to the length of each side of your patio. Lay them on edge around the perimeter, with the top edge at the height you want the finished concrete to be. Drive wooden stakes (2-by-2 or 2-by-4 scraps, 18 to 24 inches long) on the outside of the boards every 3 to 4 feet, and nail or screw the boards to the stakes.
Use a 4-foot level to check that the boards are level side-to-side and slope slightly away from the house (one-eighth inch per foot). Adjust the stakes by driving them deeper or adding shims underneath until the boards are correct. The formwork will bow outward when you pour the concrete, so stake it firmly—loose formwork is the second most common mistake.
For curved edges, use flexible hardboard or thin plywood instead of 2-by-4s, and stake it more frequently (every 1 to 2 feet) to hold the curve.
Mix or order the concrete
Calculate the volume of concrete you need: multiply length × width × depth (in feet), then divide by 27 to get cubic yards. For example, a 10-by-12-foot patio that is 4 inches deep is 10 × 12 × 0.33 ÷ 27 = 1.5 cubic yards.
For patios smaller than 2 cubic yards, you can mix concrete yourself using bags of concrete mix and a power mixer (rented for $40 to $60 per day). For anything larger, order ready-mix concrete from a local supplier—it arrives in a truck and is poured directly into your formwork. Ready-mix is more consistent and faster, but the truck must be able to reach your patio and you must be ready to pour when ready when it arrives.
If mixing by hand, follow the bag instructions for water ratio. Concrete should be thick enough to hold a footprint but wet enough to flow into corners. Too dry and it will not level; too wet and it will sag and crack as it dries.
Pour and level the concrete
Start pouring concrete at one corner and work toward the opposite corner, filling the formwork evenly. Do not dump it all in one spot. Use a shovel or concrete rake to spread it and push it into corners and against the formwork.
Once the formwork is full, use a straight board (a 2-by-4 or 2-by-6 longer than the width of the patio) laid flat across the top of the formwork. Drag the board across the surface with a sawing motion, moving from one end to the other. This levels the concrete and removes air pockets. You may need to do this twice. The surface should be flush with the top of the formwork and smooth.
Work quickly—concrete begins to set within 30 to 60 minutes, depending on temperature and humidity. On hot days, it sets faster. On cold days, it sets slower.
Finish the surface and add control joints
Once the concrete is level, you can finish it several ways. A broom finish (dragging a stiff broom across the surface) creates texture and prevents slipping. A troweled finish (smoothing with a metal trowel) looks polished but is slippery when wet. Most patios use a broom finish.
Before the concrete hardens completely (usually 4 to 8 hours after pouring), cut control joints into the surface using a concrete saw or a jointing tool. These are shallow grooves that run every 4 to 6 feet in a grid pattern. Control joints guide cracks to happen along the joints instead of randomly across the patio. Without them, the concrete will crack as it shrinks during curing.
If you do not have a concrete saw, you can score the joints with a straightedge and a grooving tool while the concrete is still soft (usually 6 to 12 hours after pouring).
Cure the concrete and remove formwork
Cover the patio with plastic sheeting and weight down the edges with boards or rocks. This keeps rain off and slows evaporation, which actually speeds curing and reduces cracking. Leave the plastic on for at least seven days.
Do not walk on the patio for seven days. After seven days, you can remove the plastic and walk on it carefully. The concrete reaches full strength after 28 days, so avoid heavy loads (like moving a grill or parking a car on it) until then.
Remove the wooden formwork after the concrete has set for at least 24 hours. Pull the nails or unscrew the boards, then pry them away from the concrete. Fill any gaps left by the formwork with concrete caulk or mortar.
Frequently Asked Questions
What if it rains while I am pouring or before the concrete sets?
Rain during pouring dilutes the concrete and weakens it. If rain is forecast, cover the area with a tarp before you start. If it rains after you pour but before the concrete hardens (within the first 24 hours), cover it when ready with plastic. Light rain after 24 hours is usually not a problem, but heavy rain can damage the surface.
How do I fix cracks that appear after the patio is done?
Small hairline cracks (less than one-eighth inch wide) are normal and do not affect the patio's strength. Wider cracks can be filled with concrete caulk or a concrete patching compound. Clean out the crack first with a wire brush, then explore the filler according to the product instructions.
Can I pour a patio in winter or very cold weather?
Concrete sets much slower in cold weather and can be damaged by freezing before it hardens. Avoid pouring when the temperature is below 50 degrees Fahrenheit. If you must pour in cool weather, use concrete accelerator (added to the mix) and cover the patio with plastic and blankets to retain heat.
What tools do I actually need to rent versus buy?
Rent a power mixer (if mixing by hand), a plate compactor, and a concrete saw. Buy or borrow a shovel, level, wheelbarrow, rake, broom, and straightedge. A power mixer costs $40 to $60 per day; a plate compactor costs $50 to $80 per day. Buying these tools for a single patio is not worth the cost.
How much does a cement patio cost?
Material costs vary by region and concrete prices, but expect to spend $3 to $8 per square foot for concrete, gravel, and formwork materials. A 100-square-foot patio (roughly 10 by 10 feet) costs $300 to $800 in materials. Labor costs vary widely depending on your location and whether you hire a contractor.