I like doing concrete DIYs and repair projects around the home, in the yard, decks, and pathways, and have come across people asking if they can pour concrete in the rain.
Can concrete be poured in the rain?
Yes, concrete can be poured in the rain. However, there are exceptions and it’s not well recommended.
Here’s the deal…
Water is usually a part if the concrete mixture and enables it gain strength.
However, if there is too much water, especially in the form of a downpour, it is likely to cause more harm than good.
Too much water causes the concrete to lose strength, causing dusting and scaling.
Unfortunately, once damage is done, it is hard to repair the problem. Read on to know what to do if there is a sudden downpour when preparing or actually pouring concrete.
You can pour concrete onto your surface even during wet weather. However, you should be careful about the water-concrete ratio as it affects the hardness of the resulting concrete block.
In essence, concrete does not dry but cures. Curing is a chemical reaction that causes concrete to harden in presence of water. If the mixture cures without problems, it is more likely to be strong.
What Not to Do When Pouring Concrete in Rain
If it rains when pouring concrete, never pour concrete into cavities filled with water.
This water will soak up concrete and cause weakness. Drain the water and create a drainage system to prevent it from filling up again.
On the other hand, if it starts to pour as soon as you have laid a concrete slab, avoid letting water flow on the surface.
Drainage water will not only damage the finish of your concrete, it will also leak into the concrete and cause weakness.
However, if four to eight hours have passed since you poured the concrete, it has cured to the point that it is hard enough to walk on and rain will do minimal damage.
Therefore, nothing needs to be done on the surface. However, you may still want to avoid surface runoff on the concrete surface.
Other Considerations When Pouring Concrete in the Rain
Plan for the Rain
In rare cases does it rain without earlier warning signs.
If you are pouring concrete during wet season, check the weather forecast on the date of your work. If rain is expected, look for plastic sheet to apply on the top of the concrete after pouring it. The simple solution prevents water from mixing with fresh concrete and weakening it.
Postpone the Concrete Pour
If you are dealing with really heavy rainfall, you may want to hold on for some time before pouring concrete.
This may save you from extensive draining of water, covering large sections of the work area and repairs from storm damage. Most heavy rain lasts for one two hours, which is not a very long wait.
You may have covered the concrete, but if there is surface runoff coming over the fresh concrete, you will end up having the same problem you were trying to avoid.
Therefore, it is recommended that you dig drains around the work area to lead the water away, especially if it is on the lower part of a slope.
Assess the Situation After a Storm
Sometimes it may rain just after pouring concrete and cause extensive damage on the surface and in the slab.
It is important to check the kind of damage that has been done to the slab and do corrective measures before the curing process has gone on.
You can start by checking the surface for any damage.
Ponds and bumps filled with water are a tell-all sign that you need to rework the surface. You may also carry out a hardness test to find out if the curing process has started.
If the curing has not yet started, you may have to compact the concrete once more to cover any spaces that may have been created by additional water seepage.
Repairs on wet, fresh concrete are cheaper and easier than on cured slabs.
However, if the curing has started, you may only repair the sections that were damaged by the water.
Can I Pour Concrete When It’s Raining?
Yes, you may pour concrete during the rainy weather.
However, you should take precautions to prevent damage from excess water. Here is a quick look at the steps to take.
• Check the weather forecast for the day of the concrete pour.
• Postpone the concrete pour until the weather is better where possible.
• Get plastic covers to prevent rain from beating the concrete surface.
• Drain the water after the rain before pouring the concrete into cavities.
• Create a drainage around the concrete slab to guide the surface runoff away from the work area.
• If you did not have enough time to cover your work surface and the concrete was affected by rain, assess the damage and make the right repairs.
If you are doing a DIY project and believe that your concrete slab may have some weaknesses, you may consider the help of a professional contractor to ascertain the extent of the damage.