Can Concrete Be Poured In Rain? Let’s Find Out

After the long and dreadful winter, spring arrives, and with it comes the warm embrace of sunshine and rain. While it’s a great season to go out and about, it might become a bit of an obstacle for those planning on laying concrete.

This begs the question: can concrete be poured in rain?

The short answer is: it’s not recommended. While rain can be refreshing and even beneficial to some aspects of life, it’s not very helpful when it comes to pouring concrete. This is because the rain can cause the concrete to be more porous, with more air pockets and cracks. 

Weak surfaces, bleeding, surface cracking, shrinkage, and other issues can also arise due to moisture These effects can be amplified in rainy weather when mixed with the power of wind and whipping rain.

Technically speaking, you can pour concrete during the rainy season, however, this comprises the strength and raises the tendency of the concrete to crack.

Therefore, if you plan on pouring concrete at your property or have some renovations planned that involve it, it’s best to avoid rainy days and wait for a sunny day before proceeding with the project.

can concrete be poured in rain

Can You Pour Concrete In Rain? If So, How?

You can pour concrete in the rain but avoid heavy rain weather. Heavy rain may wash out some cement from the surface, leading to inappropriate surfacing with cracks or other issues.

But if you have any deadline to complete the project, here are some tips and precautions to take into consideration when pouring concrete in the rain:

Don’t Let Rainwater Stay Under the Concrete

Make sure that the area is properly drained to prevent any water from staying under the concrete. Clear the collected rainwater from the surface and let the surface be free of excess water.

Additionally, make sure to check the surface on which you are going to pour concrete is dry before starting. Never make the mistake of pouring concrete onto wet surfaces or water-filled cavities.

Plan Ahead Of Time By Checking The Weather

This might seem like common sense but check the weather forecast beforehand, and if you detect too much rain in the forecast, it’s best to plan accordingly.

Also, ensure to have a plastic sheet or any waterproofing materials ready to cover the work site.

water flowing along the street curb during heavy rain. Close up of splashing raindrops and air bubbles.

Use Less Water In The Concrete Mix During Rainy Days

If you are storing aggregates outside, rainwater will make your crushed stones and sand wet. It will automatically add additional water to your concrete mixture; hence, use less water while making a concrete batch.

Additionally, keep an eye on your cement and ensure that no moisture gets into the bags wherever you store them. You must store cement in a dry environment as the water may get mixed with cement and can set or cure it faster than you realize.

Stop Pouring If It Starts Raining

In the event that it starts to rain in the middle of your project, stop the pouring process and cover everything with plastic sheets. In this way, you can prevent further saturation of the base, which leads to a weak surface.

Dry The Surface

A large amount of standing water on top of newly poured concrete can leech cement and produce more issues that may damage the end product. Ensure to brush off surface water before covering.

Check And Install Good Drainage

Good drainage will ensure no rainwater pools in trenches dug for slabs, driveways, or footings. So, it is vital to ensure good drainage because rainwater can also bring contaminants. There will not be any issues pouring concrete in the rain unless the water drains away.

Perform Proper Inspections After Raining

Once the rain has passed, inspect the concrete and find out the damage or water pools on the surface, if any. Perform a simple scratch test to determine whether the concrete surface has any adverse rain impact.

Just in case you find any problem, address it immediately since leaving the problem to worsen can lead to more damage. Smoothen the surface with a float or concrete trowel to remove the water pools.

Waterproofing Covers and Sealants

If the weather conditions are very harsh and you are having no luck with pouring concrete in the rain, consider investing in waterproofing covers that you can use to cover your work area and keep it dry. Also, look for sealants to protect your fresh pour from any further damage.

Trowels next to a new, freshly poured concrete foundation. It is raining and part of the concrete has been covered with a tarp.

Be Ready With The Correct Types Of Materials And Equipment

Ensure to have adequate types of materials and equipment like plastic sheets, waterproofing covers, sealants, a power float, etc handy when pouring concrete in the rain.

This will help you to keep your work area dry and make sure that the concrete does not get affected by water.

Monitor the Temperature

Keep an eye on the temperature because concrete may lead to cracks or get uneven during cold weather. If the temperature lowers and gets down more in the rainy season, you can see damage in the poured concrete, so be ready with the additional heated enclosure.

Can You Pour Concrete After Or Before Rain?

Yes, you can pour concrete before or after rain. But make sure to check the weather conditions and properly dry the surface before you start your work.

If you pour concrete before the rain, you need to check the weather forecast and get ready for heavy rain.

Cover the poured concrete with plastic or waterproof covers and materials so that your freshly laid surface may stay rain-free for at least 6 to 8 hours. After eight hours of the concrete pouring process, the strength of the concrete will be enough to resist heavy rainfall.

On the other hand, if you finish pouring after a rain shower, make sure to dry out the surface before covering it with plastic sheets or waterproofing covers. This way you can prevent further saturation and keep your work from being ruined by water.

You must also inspect concrete for any water pooling and perform a scratch test to determine the effects of the rain on your concrete.

How Rain Impacts Concrete Pouring?

The effects of rainwater depend on the curing stage it reaches before rain occurs. If you have poured concrete already and it has passed about 5 to 6 hours, its effect will be minimal. But if rain occurs after pouring concrete immediately or in a short time, then it may lead to some damaging effects such as:

  • Rain falling on the freshly poured concrete may harm the entire surface and the float/ level finishing.
  • If extra water makes its way to the concrete mix, the result will get worse. It can lead to weak concrete overall.
  • Washing of concrete may also occur if there is heavy rain, resulting in uneven bumps on the surface.
  • Before pouring footings, driveways, or slabs, rain may have a detrimental effect if the subgrade is oversaturated. It may result in ponding because the extra water gets absorbed by fresh concrete, which automatically changes the ratio of water-cement.
  • Rain may also wreak havoc on freshly poured and sealed concrete that may cause the sealer to blister and bubble. (Tip: Ensure to apply sealer when it can stay rain-free for 24 hours after sealing.

Hence, for this reason, it is crucial to check out the weather forecast before pouring concrete in the rainy season. Also, ensure to follow some tips and take precautions beforehand.

Frequently Asked Questions

How Long Does Concrete Take To Cure?

If the weather forecast has mentioned how long it’ll take before it rains, take into account that concrete cures in about 6-8 hours. With that in mind, make sure to cover your concrete with plastic sheets or waterproofing covers, and keep it dry.

How To Check If Rain Has Caused Damage to Concrete?

Perform a simple scratch test. Also, inspect the entire surface and find any water pool or other damage.

Can You Pour Concrete On The Wet Ground?

You need to let it dry or cover the wet ground with the tarp before pouring it to prevent water on the ground. Wet ground is not a good base for fresh concrete pouring.

What Happens If It Rains After 2 Hours Of Concrete Poured?

There might be some damage such as water pools, decreased strength, and uneven bumps. And if it gets the space to enter the concrete mix surface in-depth, you will find the cracks, bents, or other problems within a short time.

What Is The Best Time To Pour Concrete?

The perfect time to pour concrete depends on the area you live. The temperature must be between 50 to 60 degrees Fahrenheit for most of the day. According to your area, the season can be spring, winter, or fall.

Note: Remember that the best time to pour concrete is during the moderate months of the year.

Final Thoughts

We hope you now have a better understanding of how rain affects concrete pouring and what should be done to prevent further damage.

Technically, it’s possible, but not recommended. It is always better to keep the freshly poured concrete dry for more strength and durability.

Keep the weather in mind before you start pouring concrete and prepare accordingly. And make sure to follow all the tips and precautions mentioned in this article.

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