Effects of Pouring Concrete in Hot Weather

While extreme weather can pose difficulties for concrete projects, most qualified concrete contractors can overcome the challenges to deliver a beautiful final product.

Though summer is an ideal time for concrete jobs, its not without its challenges. In particular, pouring concrete in hot weather can be especially tricky. During the warm summer months, we here at GWC Decorative Concrete will take extra care of the following factors:

  • Moisture Loss
  • Temperature Fluctuation
  • Wind and Radiant Heat
  • Concrete Cracking
Pouring concrete in hot weather portland

Moisture Loss

In hot and dry climates, such as our typical Northwest summer, concrete will tend to lose moisture at a rapid rate, particularly at the surface.

When the surface of your new concrete dries out at a rapid rate, it can become brittle. The concrete beneath the surface will also dry and set at a slower rate. Since the concrete at the surface is shrinking faster than the rest of the pour, there is likely to be cracking and an overall lack of integrity in the slab.

Temperature Fluctuation

When the weather is particularly hot and dry during the day, we often see a rapid temperature decline once the sun sets. This thermal fluctuation can wreak havoc on your concrete pour. The same principle here applies as when you drop a cold piece of glass into boiling water. The resulting cracking can be fatal to your brand new slab.

Wind and Radiant Heat

The wind and direct sunlight can also impact your concrete pour.

Even if the weather is humid, a high wind can cause rapid drying at the surface of your slab. Direct sunlight can also prematurely draw moisture from your concrete and result in a cracked, botched job.

Concrete Cracking

In times of high temperatures, as we are starting to see even in Portland and the Northwest in general, there are precautions that a concrete contractor can take.

It is important to hydrate the gravel prior to pouring as well as pouring it first thing in the morning. Having enough people to help pour equates to more manpower and less concrete used to maintain a quality job.

Covering the pour with a tent is an effective technique for keeping direct sunlight off the concrete. Sometimes a tent is not enough, and it is better to be patient and plan to complete the job on a cooler day.

There are also spray coatings that can help maintain the moisture on the surface, which are lightly colored to reflect radiant energy back to the atmosphere.

Let’s Get Started!

A new concrete pour can open an exciting chapter in the life of your home. Click through our portfolio for design inspiration and when you’re ready for your free consultation, contact GWC Decorative Concrete.