Concrete Curing Time Charts for Homeowners and DIYers

Peter Chambers

May 16, 2024

Concrete up close

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A concrete curing time chart can help you figure out how long it’ll take for your new driveway, sidewalk, foundation or garage floor to cure. Our charts adjust for temperature, moisture, concrete type, thickness and strength gain. 

The Basic Concrete Curing Time Chart for Beginners 

Concrete curing is the process of making sure the mix retains enough moisture and maintains the right temperature to ensure long-term durability. Drying is the process by which the mix physically dries and reaches its full strength. 

Curing StageConcrete Surface Strength
24-48 hoursCan support people.
7 daysCan support vehicles and equipment.
28 daysCan support heavy machinery.
The Weight Each Concrete Curing Stage Can Support

Generally, concrete is safe to walk on after curing for 24-48 hours. After seven days, it should be solid enough to support machinery and equipment. It reaches its near-full strength at 28 days — what engineers consider fully cured — and is safe to use for any purpose. 

What Is the Ideal Temperature for Concrete Curing?

Temperature and humidity are two of the main factors that impact curing duration. If concrete cures too slowly or quickly, its strength will diminish — and fractures have a much higher chance of appearing sooner. 

Curing StageIdeal Temperature Range
7 days68-77 degrees Fahrenheit
7-14 days59-68 degrees Fahrenheit
14-28 days50-59 degrees Fahrenheit
Recommended Temperature Ranges for Concrete Curing 

Concrete should stay at 68-77 degrees Fahrenheit within the first seven days of curing. Then, it should maintain a temperature of 59-68 degrees Fahrenheit until it reaches the 14-day mark. After that, it should stay within the 50-59 degrees Fahrenheit range until it fully cures at 28 days.

How Does Temperature Impact Concrete Curing Time?

Naturally, engineers and construction crews can plan for one circumstance and end up with another — nature doesn’t care whether they’re in the middle of curing concrete. If the temperature deviates from the optimal range, their curing duration changes.

Curing DurationTemperature Range
3 days at most90 degrees Fahrenheit and above
5 days75-90 degrees Fahrenheit
7 days60-75 degrees Fahrenheit
14 days54-60 degrees Fahrenheit
28 days at least45 degrees Fahrenheit and below
Concrete Curing Time Chart Adjusted for Temperature

As you can see in this concrete curing time chart, while concrete curing only takes a few days in optimal conditions, it accelerates as temperatures rise. Unfortunately, extreme heat quickly deteriorates the mixture’s strength. Maintaining 50-80 degrees Fahrenheit is generally ideal. 

A person smoothing concrete.
Direct sunlight and high temperatures accelerated the rate of concrete curing.

Concrete can cure in three days or less if the temperature is 90 degrees Fahrenheit and above. At 75-90 degrees Fahrenheit, it lengthens to five days. It takes seven days in the 60-75 degrees Fahrenheit range — close to optimal conditions. At 45-60 degrees Fahrenheit, it takes 14 days. When the temperature is 45 degrees Fahrenheit and below, it takes at least 28 days.

What Is the Ideal Humidity Range for Concrete Curing?

If concrete’s moisture content is too high, its curing duration lengthens. If the mixture dries out too quickly, it will become much more prone to deterioration and the surface will be littered with hairline fractures.

Curing StageIdeal Humidity Range
7 days95% humidity
7-14 days80% humidity
14-28 days60% humidity
Recommended Moisture Ranges for Concrete Curing 

Concrete should maintain a specific moisture content while curing to achieve maximum strength and allow for optimal durability. As such, the humidity shouldn’t exceed 95% within the first seven days. Then, it drops to 80% until the 14-day mark and 60% until the 28-day mark. 

What happens if it rains days after pouring concrete? The droplets can damage the concrete’s surface, making it uneven and compromising the float finish — meaning it will get a pitted texture and potentially become less compact. 

Wet concrete
Rain can compromise the concrete’s float finish.

While wet-curing — the process of keeping concrete wet for 28 days — exists, it requires special tools. Also, its viability depends on the concrete’s mix, treatment needs and cure compound. Besides, it’s only really used if the temperature exceeds 85 degrees Fahrenheit.

How Does Concrete Type Impact Concrete Curing Time?

Other than temperature and moisture, the other two main factors that influence concrete curing time are cement type and mixture ingredients. Depending on which one you or your contractors use, your curing time can lengthen. 

External Curing DurationConcrete Type
7 daysType I, ASTM C150 (standard Portland cement)
10 daysType II, ASTM C150 (sulfate-resistant cement)
3-5 daysType III, ASTM C150 (high-strength cement)
14 daysType IV, ASTM C150 (low-heat Portland cement)
14-28 daysType V, ASTM C150 (high-sulfate resistant cement)
Concrete Curing Time Chart Adjusted for Concrete Type

According to the American Concrete Institute (ACI) — the ACI 308 Guide to the External Curing of Concrete, to be precise — standard Portland cement takes seven days to cure externally. Sulfate-resistant takes 10 days, high-strength takes 3-5 days, the low-heat Portland variant takes 14 days and the high-sulfate-resistant version takes 14-28 days. 

How Does Slab Thickness Impact Concrete Curing Time?

The duration of internal curing varies depending on the thickness of the pour. The mixture’s water-cement (WC) ratio is a deciding factor you should account for. Typically, it ranges between  0.4 and 0.6, depending on the type of concrete mix used. 

Slab ThicknessWC 0.4WC 0.5WC 0.6
4 inches20 days36 days54 days
6 inches40 days72 days108 days
7 inches50 days90 days135 days
Concrete Drying Time Chart Adjusted for Thickness: Upper-Floor Slabs
Slab ThicknessWC 0.4WC 0.5WC 0.6
4 inches40 days83 days140 days
6 inches80 days165 days280 days
7 inches100 days208 days351 days
Concrete Drying Time Chart Adjusted for Thickness: On-Grade Slabs

For the sake of simplicity, this concrete curing time chart assumes the temperature is 65 degrees Fahrenheit and the humidity is 60% — standard operating conditions. The figures represent the goal of a 4% moisture content at 75% relative humidity. 

A hole filled with concrete
The thicker the concrete, the slower the curing time.

How long does it take for four-inch concrete to cure? Upper floor slabs could take anywhere from 20-54 days in standard operating conditions. Depending on the WC ratio, on-grade slabs take longer — anywhere from 40-140 days.

How Strong Does Concrete Get As It Cures?

Most industry professionals recommend a minimum of seven days of curing. While the goal is to get to 99% compressive strength, it’s not uncommon for contractors to finish curing after one week — 65%-70% compressive strength is an acceptable range, as per ACI 301. 

Curing StageStrength Gain
1 day16% of its total compressive strength
3 days40% of its total compressive strength
7 days65% of its total compressive strength
14 days90% of its total compressive strength
28 days99% of its total compressive strength
Concrete Curing Time Chart by Strength Gain Over Time

On day one, the compressive strength of concrete sits at 16%. It reaches 40% of its total strength by day three. How strong is concrete after seven days? In one week, it reaches 65%. Then, in two weeks, it gets to 90%. At 28 days, it achieves 99% of its total strength.

What days are the most critical when curing concrete? Days one through 14 are the most important because they account for 90% of its total compressive strength. Generally, the rate of strength gain slows rapidly after that — it won’t reach 100% for at least one to two years. Engineers generally use the 28-day mark as the end of the curing process for this reason.

The Time Concrete Takes to Cure Can Vary Substantially 

Concrete’s thickness, mixture type, curing compound, moisture content and water-cement ratio can impact its curing time — and that’s not mentioning the significant impact temperature, sunlight, humidity and wind can have. While these charts can help you better understand general curing times, your best bet is to consult with your contractor or do the math for your location’s conditions and mixture type.

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