How Long Does it Take for Asphalt to Dry and Cure?

When investing in a new asphalt surface, the last thing you want is to use it before it’s fully dried and cured. Asphalt curing and drying are two distinct processes, both of which play a critical role in how long the asphalt lasts. Use this guide to learn all about asphalt drying and curing times based on factors like weather conditions, asphalt thickness, and air quality. 

How Long Does Asphalt Take to Cure and Dry?

Asphalt typically takes 24 to 72 hours to dry after it’s applied, but the drying time can vary, depending on the weather conditions, asphalt thickness, and the type of mix used. Most asphalt mixes will provide recommended drying times from the manufacturer. Once it’s dry (but not cured) the asphalt driveway or other surface can endure light foot and vehicle traffic without damage.

The curing process can take up to a full year—after asphalt is cured, it has fully hardened. Over the course of the year, while the asphalt is curing, it changes color from black to dark gray as the asphalt loses its oils due to sun exposure. This process is known as oxidation. Excess oils in asphalt can lead to a “power steering tear,” or asphalt scraping from wheel rotation. While the curing process takes about a year, the asphalt can be sealed after 30 days.

Factors That Affect Asphalt Curing and Drying Time

Several factors can affect both asphalt curing and drying time, including weather conditions, air quality, and asphalt mix and thickness.

Weather Conditions

The weather is the most significant factor affecting curing and drying times. Asphalt dries and cures fastest during warm, sunny conditions, which accelerate the evaporation of moisture as well as the chemical reactions needed to cure the asphalt. Wind can help the asphalt dry faster by blowing off moisture.

When the weather is cold, rainy, snowy, or very humid, it can delay the drying process as it increases moisture and takes longer for it to evaporate. These conditions make the asphalt slower to cure as it delays the chemical reactions needed to fully harden it. 

Asphalt Mix 

Asphalt comes in a variety of mixes, which vary by the type and grade of binder used, as well as aggregate size and distribution. Dense-graded asphalt with a high number of fine aggregates takes longer to cure than less dense asphalt with fewer and larger aggregates. Consult the manufacturer of your asphalt mix for recommended drying and curing times. 

Asphalt Thickness

The asphalt’s thickness can also affect drying times. Basically, the thicker the asphalt layer, the longer it takes to dry and cure since heat and moisture must travel a greater distance to escape from the asphalt’s interior to the surface. 

Air Quality and Altitude

Poor air quality and a lack of oxygen content in the atmosphere can delay asphalt curing times since it slows down the oxidation process of the binder, which is necessary for the asphalt to fully cure. Additionally, higher altitudes usually have lower air pressure and cooler temperatures, which can delay the evaporation of moisture from the asphalt, increasing drying time.

What is the Difference Between Curing and Drying?

Curing and drying refer to two distinct phases of the asphalt setting process. Drying is the first phase, which is when the water in the asphalt fully evaporates and leaves the surface dry to the touch. Once the asphalt is dry, it’s firm enough to bear weight, but you still need to take precautions until it’s fully cured.

The curing phase happens after drying. It’s a longer process during which the asphalt continues to harden and gain strength over time. During this process, the asphalt binder, which is typically petroleum based, reacts with the asphalt’s aggregate materials to form a durable structure.

Maintenance Tips for New Asphalt

If your asphalt is dry but not yet cured, take some precautions to preserve its appearance until it fully hardens. The following maintenance tips can keep your asphalt in great condition during this critical period. 

• Don’t use the new asphalt surface until it’s completely dry, which can take anywhere from 24 to 72 hours. 

• Avoid using sharp objects or heavy equipment on the asphalt until it’s cured. Otherwise, you can dent the surface.

• Regularly inspect your new surface for any signs of distress, like cracks and potholes, and repair the asphalt quickly to prevent further issues. If you’re not comfortable with repairs, you can always hire an asphalt pro to address them for you. 

• Be careful with petroleum-based products, like oil and gas, which can dissolve the asphalt binder and weaken the surface if spilled.

• Promptly remove any vegetation that might sprout through the asphalt, like weeds, to prevent cracks and other damage.

• Avoid making very sharp turns or sudden stops with your car—it can scuff the asphalt’s surface before it’s fully hardened. 

• Ensure that water is draining away from the asphalt since standing water can weaken the surface and lead to damage, particularly during the early stages of curing.