To pour, or not to pour?
Can you pour concrete when it’s raining?
To pour, or not to pour—when it’s pouring? That is the question, especially if you’re wondering about less-than-perfect weather. If you’ve planned a concrete project but there’s rain on the horizon, you may want to reschedule until sunny skies return. Why? Keep reading as we walk you through our answers to some of the most common rain + concrete questions.
Common questions about concrete and the weather
Q: Can you pour concrete when it’s raining?
A: In general, it’s not a good idea to pour concrete when it’s raining, snowing, or hailing. For optimum results, pick a clear day.
Q: Ok, but why not?
A: A little sun shower or sprinkle won’t do too much damage to the concrete, but a deluge introduces too much moisture to the mix. In addition, rain can make the jobsite muddy and watery and generally difficult for concrete trucks to access.
Q: But doesn’t concrete need moisture?
A: Well, yes. Concrete can lose up to 50% of its strength if there’s not enough moisture. But it needs it in the mixture, not saturated on top in big puddles which can leach cement from the area and result in a weak and cracked finish.
Q: What if there’s no choice and it’s raining?
A: Make sure you prep the site with tarps or plastic sheeting to keep the area you are working in dry both above and below the site, and create good drainage.
Q: Should you pour concrete if it’s going to rain a few hours after you do it?
A: Nope. Unless you really have to, in which case you should cover the site completely once you’ve poured your concrete.
Q: Does temperature matter?
A: It surely does! Ideally, concrete should be poured in moderate temperatures above 50°F (10°C). But before you start throwing bags of cement around, check your forecast. Ideally, the temperature should stay uniform for the next few weeks, too, without big highs or lows.
Q: Why does the temperature need to be stable?
A: Two words: curing process. After you pour your concrete, it needs the right temperature and moisture to “cure” properly. Otherwise, you’re going to get some ugly cracks, sogginess, a weak finish, or other terrible-no-good results.
Q: Help! What if the temperature drops unexpectedly?
A: Insulate, insulate, insulate. In other words, your concrete needs a coat to prevent it from cooling too quickly. Insulated blankets or foam work in a pinch. Pay special attention to covering the surface, edges, and corners. And whatever you use, make sure it’s secure so the wind can’t blow it off!
Find concrete solutions
Feeling inspired by this Q&A? If you’re ready to tackle your next concrete-based project (when it’s not raining), check out our Services page.. See how we can help you find concrete solutions!