How long after concrete is poured can it be rained on?

This article will answer the question “How long after concrete is poured can it be rained on?” It will also talk about how rain-damaged concrete may be prevented and remedied by following these guidelines. Once the damage has been done, it may be challenging to repair and can frequently affect the final aesthetic of the surface. Don’t let the bad weather dampen your spirits! 

How long after concrete is poured can it be rained on?

Concrete needs between 4 to 8 hours to be poured to be rained on. All concrete is made up of water and cement, which hydrates and strengthens it. On the other hand, driving rain may do much more damage than good to newly mixed concrete. Concrete poured in the rain is more susceptible to dusting and scaling, making it less durable.

Concrete Pouring in the Rain: what are the tips and tricks?

There is no guarantee that a rainstorm will occur despite weather-predicting technologies and radar maps, particularly during the rainiest months.

Consider postponing a significant concrete pour until the weather improves if rain is expected. Always have a plastic sheet or tarp ready to cover the concrete, even if rain isn’t expected. This is a precautionary measure. It’s essential to seal the borders so that rainwater can’t get beneath.

Be sure to check the worksite for gutters and downspouts before construction starts. Concrete may be carved out of wet concrete by rainwater flowing from downspouts or over the edge of a roof that does not have gutters.

What are the ways to protect fresh concrete from rain?

  • There are different ways of protecting concrete from rain; weather prediction should be checked before placing new concrete so that you don’t have to scramble for equipment and are prepared to take measures. 
  • Adding more water than required to the concrete mix compromises the strength of the mix and increases the chance of cracking, and it also impacts the strength of hardened concrete, which is why it is so important to use the correct amount.
  • If you want to avoid long-term damage caused by precipitation, you must ensure that the area where you’re ready to mix concrete is well protected.
  • The concrete’s intrinsic strength might also be affected by rain. The curing process might be slowed down if there is a lot of rain for a few days in a row. 
  • As a result, the concrete mixture may not be as potent as it could have been.
  • It’s a good idea to inquire whether rain is a possibility if another concrete company is installing the ready mix concrete on your behalf. 
  • To prevent the ground from becoming sodden on the day of the pour, you should cover the area with plastic sheets and tarps.
  • The concrete will absorb the moisture and become weakened if it is poured into a water-filled cavity or onto a damp surface.
  • Make sure to push any surface water away from the border of the slab while pouring concrete after a rainstorm.
  • It’s best to have plastic sheets and wood on hand in case you run out of time to build anything over the new concrete.

What is the concrete drying time prior to rain?

After pouring concrete, even if it rains right after, the damage may not be too bad. You may be able to avoid significant damage from rain if the finishing procedure was completed in enough time and the concrete has hardened (usually between 4 and 8 hours after mixing).

After the concrete has cured, water on the surface is perfect since it promotes the hydration and curing of the concrete. 

Test the surface’s integrity and whether or not rain had any effect with a simple scratch test utilizing a screwdriver or a Mohs concrete surface hardness scratch kit.

What are the Rain-Induced Problems for concrete?


  • Oversaturating the subgrade with rain may create ponding even before you lay a concrete slab. 
  • Water may be absorbed by freshly mixed concrete, causing a change in a concrete mixture’s water-cement ratio. 
  • Rain may also cause recently sealed concrete to bubble and blister, causing the sealer to peel off. Apply the sealer when it hasn’t rained for at least 24 hours.

What is the effect of rain on concrete?

  • The most significant impact of rain on concrete you may encounter is the concrete’s surface after it has been wet. 
  • We all know that water is an essential element in concrete. Still, excessive water use may weaken the concrete, making the rainy season much more difficult because of the combination of water and wind. Surface scaling on concrete surfaces may also occur as a result of rainfall. 
  • The concrete’s surface will become flaky as a result of surface scaling. However, even if it may not be apparent, it may shatter or crumble if you begin to walk on it or store your appliances and other products there. To preserve the concrete’s strength lasting longer, this must be limited.
  • Concrete that has just been poured may be damaged by heavy rain, which can remove part of the cement from the mix. Concrete’s strength may be reduced as a result of this process.
  • Assuming that no protective covering had been in place before the rain, and if the hardening process had not progressed far, part of the cement might have been washed away by rain. 
  • In the end, you’d be left with a weaker surface that might lead to future issues. The surface may be dusted, the surface is not sealed, and the slab’s capacity to resist breaking due to freeze-thaw cycles may be decreased. 
  • Scaling might be a much worse problem, especially if it’s raining hard and fast. A concrete surface that resembles the flaky layers of a croissant is the outcome. 
  • The scale may be seen when the slab has been walked on, but it can also be hidden until the scale breaks or crumbles away. If you haven’t paid for your patio yet, you may want to ask the contractor who installed it for a one-year guarantee. 
  • As a consequence of the excessive rain, there may be surface issues that need to be addressed.
  • Keeping water on the concrete throughout the hydration stage, on the other hand, is good. Water is an essential need in this process. 
  • In the event of ponding, for example, the surface of the concrete may get discolored. This is the only negative. Furthermore, its strength and durability should be unaffected by the presence of excessive water.


Is water to cement ratio important for concrete?

Keeping an eye on high water to cement ratio is also important. In an unprotected combination of components, excessive rain may alter the water-cement ratio in the mixture. 

The ratio may be changed to make the concrete easier to pour, but the concrete’s strength and durability will be weakened as a result.

It’s a recipe for disaster if it’s put together this way. For all your hard work in producing the mix and putting it into place, it will be prone to cracks, which will ruin all of your hard work.


What are the effects of concrete on curing?

Depending on when the rain started, rainwater may alter concrete in a variety of ways. Covering the concrete while still fresh (about 2-4 hours after pouring) is critical for its safety. 

As soon as the concrete is done (between 4 and 8 hours after it has been poured) and has set enough for walking, there should be little or no influence from rain. 


How to pour concrete in rain?

When it rains, contractors must keep an eye on their concrete constructions. The concrete’s surface look and interior strength may be affected by rain. 

Patch marks and pores may appear in the wet concrete while the concrete is between its initial and final settings. This may be affecting the concrete’s curing process before it has had a chance to harden fully.

What precautions could be taken in the rainy season?

During the rainy season, use less water in your concrete mix. Rain will inevitably soak your aggregates if you keep them outdoors. When producing a batch of concrete, remember to use less water since this will increase the amount of water in the mix. 

Keep a watch on your cement and ensure no moisture gets into the bags while it’s being kept. At all times, the cement must be kept in a dry atmosphere.


What are the additives that could protect concrete from water damage?

Admixtures with hydrophilic crystals may be helpful during the rainy season. When mixed with water and cement, these admixtures create calcium silicate. 

As a result of these crystals, the concrete is protected against water infiltration by clogging pores and microcracks. They protect the concrete from water damage by sealing it. 


When pouring concrete should be avoided?

Make sure the weather isn’t too rainy or windy before you begin pouring concrete. If you can’t locate 12 hours without rain in the forecast, you may want to look elsewhere. Any rain might delay the curing process of freshly poured concrete by around 12 hours. 

When it comes to curing, the wind may also have a detrimental effect on the process. When the concrete is exposed to strong winds, it might bleed and alter the pace at which its interior moisture evaporates.


Is checking up on the weather forecast before concreting important?

When it rains, traffic on the road might be affected. Fresh concrete batches may be unable to be delivered on time if this delays them. Suppliers need to keep an eye on the weather and avoid delivering when it rains. 

Plan for other routes with less traffic if this is not practicable. In the long run, delays in the laying of concrete limit its workability, reducing its elasticity. It will cost the project money and enable water to get into the building site if delivery delays occur.


How could waterproof covers shield the concrete from rainwater?

During the rainy season, plastic sheeting and waterproofing canvas should be stored on-site. After pouring the concrete, cover it with plastic sheeting to protect it from the weather. Keep the concrete wet and keep the surplus water away.


Different compounds from atmospheric particulate matter dissolve in rainwater. As a result, rain has a variable composition depending on where it falls. Particulates in the atmosphere are influenced by human activities, industrial fission, local meteorological conditions, and the functions of the biome. 

As a result, concrete is sensitive to degradation when it comes into contact with rainfall that contains high carbon dioxide, acid, or sulfate levels. It is essential to grasp this process and understand the weaknesses of concrete to identify rain damage and minimize the expenditures and repairs.

Frequently asked questions (FAQS): Pouring Concrete in rain


How Long After Pouring Concrete Can It Rain?

After 2-4 hours, the concrete will still be wet and unable to withstand rain. So, it must be covered in order to protect it from the rain’s harmful effects. As long as you wait between 4-8 hours after pouring your concrete for it to harden enough to walk on without leaving a footprint, the rain should have no impact.

Can you pour concrete in the rain?

There is good news and bad news when it comes to pouring concrete. Concrete does not dry out, but rather hardens over time when it is exposed to the elements. Because curing is a chemical process, rainfall will not harm concrete. It’s unlikely that a little rain on your land would ruin your concrete project, given that concrete can be poured and dried underwater.

What impact does rain have on the fresh concrete?

The most typical issue that develops when it rains on newly laid concrete is Engineers and construction workers have a significant problem while pouring concrete during the wet season. 

In addition to the fact that rain is occasionally unexpected, its strength varies from one time to the next. We must take all precautions to prevent damage from the rain before laying concrete.

What could happen when heavy rain falls 2 hours after concrete is poured?

Damage to the concrete’s surface and floating gloss might occur if rain falls on top of newly placed concrete. When too much rainfall seeps into a concrete mix, it weakens the whole structure.

How to protect concrete from rain?

Cover the ground with plastic sheeting if heavy rain is expected a day or two before the rain pours. Learn more about concrete slab subgrades and subbases.


Larsson, R., & Rudberg, M. (2021). Effects of weather conditions on concrete work task productivity–a questionnaire survey. Construction Innovation.

Larsson, R., & Rudberg, M. (2019). Impact of Weather Conditions on In Situ Concrete Wall Operations Using a Simulation-Based Approach. Journal of Construction Engineering and Management, 145(7), 05019009

Roberts, T., Rahn, K., Dougherty, M., & LeBleu, C. (2021). Effects of Pervious Concrete Thickness on Leachate Water Temperature during Simulated Rain Events. EPiC Series in Built Environment, 2, 644-652.

Redaelli, E., Carsana, M., Lollini, F., Gastaldi, M., & Torabian Isfahani, F. (2019). Sustainable concrete with seawater and corrosion resistant reinforcement: results of monitoring of corrosion behaviour.

Shang, L., Wu, C., & Yin, X. (2018, April). Discussion on mass concrete construction of wind turbine generator foundation. In AIP Conference Proceedings (Vol. 1955, No. 1, p. 030004). AIP Publishing LLC.

Fan, Y. F., Hu, Z. Q., Zhang, Y. Z., & Liu, J. L. (2010). Deterioration of compressive property of concrete under simulated acid rain environment. Construction and Building Materials, 24(10), 1975-1983.

Chini, S. A., & Mbwambo, W. J. (1996, October). Environmentally friendly solutions for the disposal of concrete wash water from ready mixed concrete operations. In CIB W89 Beijing International Conference (pp. 21-24).