People say concrete "dries", but it actually hardens through a chemical reaction with water, called curing. That is why keeping it damp early helps it get stronger.
Typical timeline
| Time | What you can usually do |
|---|---|
| 24 to 48 hours | Light foot traffic once the surface is hard |
| About 7 days | Light vehicles, in many cases. Wait longer for heavy loads |
| About 28 days | Concrete reaches its design strength. Heavy loads and sealers |
These are typical figures for standard mixes in mild weather. Your mix, thickness and weather can change them.
Drying vs curing
The surface may look dry in a day, but the inside is still gaining strength for weeks. Strength keeps rising slowly after 28 days.
Weather matters
- Cold: below about 40°F (5°C), concrete gains strength slowly and can be damaged if it freezes early. Use blankets or cold-weather mixes.
- Hot and windy: water evaporates too quickly, which causes cracks. Pour early in the day and keep the surface damp.
- Rain: cover fresh concrete. Rain on an unfinished surface can leave it weak and dusty.
How to cure concrete well
- Finish the surface, then protect it from sun and wind.
- For the first 7 days, keep it moist by light spraying, wet burlap, plastic sheeting or a curing compound.
- Do not add water to the surface while finishing.
- Avoid de-icing salts during the first winter.
When can you seal it?
Many sealer makers recommend waiting about 28 days, but follow the product label.
Planning the pour? Use the slab calculator and read how much concrete you need for a patio.
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General information and estimates only. Follow your local building code and your supplier's instructions.