As general guidance, you can walk on new concrete after about 24 hours, drive a car on it after about 7 days, and the concrete reaches its full strength after roughly 28 days. Cold weather slows curing, so a late-fall pour in Iowa may need longer. Your contractor should give you exact timing for your pour.
The new-concrete timeline at a glance
| When | What’s generally OK |
|---|---|
| About 24 hours | Foot traffic |
| About 7 days | Passenger cars |
| About 28 days | Concrete is near full strength |
| Cold weather | Everything takes longer |
Why concrete needs time
Concrete does not dry, it cures: a chemical reaction between cement and water that keeps building strength for weeks. It hardens enough to walk on in about a day, but it is still far from its final strength. Putting a car on it too early can crack the surface or the edges before the slab has the strength to carry the load.
What slows curing down
- Cold temperatures, which are the biggest factor in Iowa from late fall to early spring
- The specific concrete mix
- Thickness and how much load the slab will carry
- Rain right after a pour
Heavier vehicles and the first weeks
Trucks, trailers, RVs and anything heavy should stay off longer than a passenger car. The safest plan is to ask the crew that poured it, because they know the mix and the weather on your pour day. At Medina Concrete we give every customer exact timing for their pour.
