Your construction project has everything set up and ready to go for a concrete pour, and then the weather takes a turn. The sky starts to darken, the winds pick up, and you start wondering how this will impact the rest of the day. You may even wonder, can you pour concrete in the rain? Pouring concrete in the rain and bad weather is not always recommended, but sometimes it is necessary to keep the project on track. There are some simple precautions you can take for a successful concrete pour in the rain.
Can You Pour Concrete in Rain?
Pouring concrete in the rain is generally not recommended because of how the increase in moisture can negatively impact the strength and durability of the concrete. Rainwater can cause the surface of the concrete to become uneven, which may lead to cracking and settling of the concrete. Rainwater may dilute the concrete mixture, which can make it weaker. Rain and dampness in the air can also cause the concrete to set too quickly, which can affect the curing process. While some types of concrete formwork and shuttering are more resistant to the elements, formwork made of wood can result in swelling and warping, which can cause deformation of the concrete surface. If rain is forecasted on the scheduled concrete pouring and curing day and you can’t reschedule, here are some steps to take for preparation and protecting a concrete pour in the rain.
Preparation for Pouring Concrete in Rain & Bad Weather
When it is not possible to reschedule the pour, and you must pour concrete in the rain, there are certain measures you can take to help minimize negative impacts on the concrete.
Construction projects tend to follow a strict schedule, and each project depends on the one before it to be completed in time for everything to come together. As much as possible, plan ahead by checking the weather to anticipate any potential rain and gather necessary materials to help prevent rainwater from impacting the concrete pour.
Keep Area Dry
Gather important materials like tarps and plastic sheets that may be used to cover the formwork and fresh concrete. Waterproof tarps and plastic sheeting can help protect the site from rain. Make sure all coverings are tightly sealed or properly anchored to withstand the risk of blowing away.
Confirm Adequate Drainage
When you cover up the job area, you also need to ensure that there is proper drainage around the concrete. Adequate drainage will ensure that no further water from the elements can get into the concrete mixture or affect the curing process. Monitor the area to check for any pooling of water above or below the tarps.
How to Pour & Protect Concrete from the Rain
Pouring concrete in the rain and protecting it from bad weather can be challenging, but it can be done. Proper planning and execution can ensure an effective pour and keep your construction project on track. These are important steps to take when pouring and protecting concrete from the rain:
Prep the Site
If you are able to anticipate any bad weather on the day of the concrete pour, then you can prep the site accordingly. This includes having materials on hand, like tarps and sheeting, to help keep the site dry. Confirm drainage areas and keep the area as dry as possible before the pouring begins.
Dry the Top
Keep an eye out for any standing water that may pool on the fresh concrete. You may need to brush off or squeegee any surface water that builds up on the concrete pour, so the curing process is not compromised.
Cover Up the Area
Cover the entire job area with waterproof tarps and plastic sheeting to ensure that no more water can get into the job site. Plan to extend tarps and sheeting several feet beyond the area on all sides to account for any gusts of wind or drainage issues.
Let it Cure
The timeline and process for curing concrete may be impacted by bad weather like rain and moisture in the area. You may need to allow for more time in the curing process depending on the weather and other factors.
Other Tips for Pouring Concrete in Rainy Weather
If your next concrete pour will take place in the rain, make sure you check the water-to-concrete mix ratio. Always keep a close eye on the poured concrete, checking for any excess water in the area that could compromise the pour. Be careful with any curing compounds or sealers that could impact the curing process. You need to use the appropriate type of admixture and follow all manufacturer’s instructions to reduce the risk of air pockets and other defects. Make sure your crew has a solid understanding of the concrete pouring and curing process and how to shift gears in bad weather and rain.
Reasons to Avoid Pouring Concrete in Heavy Rain
There are several reasons to avoid pouring concrete in bad weather, especially in heavy rain or downpours.
Too Much Moisture in Concrete
Too much moisture in the air can result in too much moisture in the concrete mix, which can compromise the integrity of the project.
Weak Top Layer of Concrete
Heavy rain can not only dilute the mix of concrete, but it can also result in reduced strength. The top layer of the concrete may become weak and more prone to cracking.
Heavy rain can also result in surface imperfections, like unevenness or cracking of the concrete. Too much water from heavy rains could also cause the concrete to cure with a rough and uneven surface finish.
Bad weather and heavy rain could damage formwork made of timber or plywood, causing the wood to swell. If the formwork is not sealed to prevent water infiltration, this could lead to the deformation of the concrete surface.
Start Building with Forming America
Forming America has the necessary services and products to help make your next concrete pour a success. Check out our inventory of concrete formwork and accessories for sale or for rent by visiting our website or contacting one of our representatives today.