Home & DIY
How long does concrete take to cure?
Estimated wait
7 days – 28 days
Typically ~18 days
Based on published sources
Timeline guide
- Faster cases~7 days
- Average cases~18 days
- Slower casesUp to 28 days
Curing ≠ drying — concrete needs moisture and >5 °C to gain strength. Letting a fresh slab dry out or freeze permanently weakens it; 28 days is a test convention, not the day hardening stops.
Concrete reaches its specified design strength at 28 days — the industry-standard test age used by the American Cement Association and NRMCA. It is typically walkable after 24–48 hours and carries light loads at about 7 days, when it has reached roughly 70–75% of design strength (ACI 308 also sets 7 days as the default moist-curing period).
More details
Curing is not drying: concrete gains strength by hydration, which needs moisture and temperatures above ~5 °C. It keeps gaining strength for months after the 28-day benchmark.
How the process works
- 1Pour and finish
- 2Walkable (24–48 h)
- 3Light loads — ~75% of strength (7 days; keep it moist until here)
- 4Design strength verified (28 days) ↑ the time on this page
- 5Keeps gaining strength for months
Last updated: 4 Jul 2026
Information is for general knowledge only.