Water is an essential ingredient in all concrete mixing with cement, causes the concrete to become hydrated and build strength. However, after freshly mixed concrete is put in place, water in the form of torrential rain could do worse than it does good. Pouring concrete during rain could weaken its structure and increase the likelihood of dusting and the formation of scaling.
When the damage is caused, it’s difficult to repair and can frequently ruin the appearance of the final surface. Don’t let the rain ruin your parade. Here are some helpful tips for preventing damage from rain and troubleshooting concrete.
Tips for Pouring Concrete in rain
Despite the advancements in weather forecasting technology and radar maps unintentionally, a rain shower could occur without warning particularly during the most humid seasons ( see these guidelines for laying concrete according to location and time of year).
If rain is predicted in the forecast, it is best to put off a major concrete pour until the weather improves. Even if you don’t expect rain it is best to be prepared to protect the concrete using the use of a plastic sheet or tarp to protect yourself in the event of. Be sure to seal the edges so that rainwater doesn’t get in.
Additionally, you should inspect the site before you begin the construction and look for the location and presence of downspouts and gutters. Water that flows from downspouts spilling over the edge of the roof with no gutters can create a trench in concrete that is wet if that slab lies directly below the overflow.
The heavy rain that follows the pouring of concrete is a problem If the concrete isn’t completed and has had sufficient time to start the initial curing process to take place. Photo by: Mr.Note19/Shutterstock
Tips to Handle Rain after Pouring Concrete
Here’s what you should do when it pours down on the freshly laid concrete
- Do not work the rainwater into the concrete surface. This is the most costly error you could make.
- Do not spread dry cement on the concrete, as it will absorb the surface water. This could weaken the finish, and also make the concrete weaker.
- Instead, after the rain has stopped, you can make use of a float to lift the water away from the edge of the slab prior to you begin to finish.
How long does concrete take to dry before rain?
Even if it begins to rain immediately after the concrete has been poured it is possible that the damage isn’t that severe. If you have sufficient time to finish the procedure and your concrete is now stiff (typically between 4 and 8 hours following mixing) rainwater can cause minor, if any, damage.
In actual fact, when concrete is set, the water that sits on the surface can be beneficial since it helps in hydration as well as cure. A basic scratch test, with a screwdriver or Mohs the concrete’s surface’s hardness test kit, could be used to determine the strength of the surface , and also check if rain had an impact on the concrete.
Spalling, or surface scaling as shown on this concrete stamped, can be due to rain weakening the strength of the concrete at or shortly after the placement.
If something happens to you and the sky begins to open on the freshly-poured concrete from the truck It’s a safe chance that rain will take some cement off the concrete near the surface.
This could cause problems like:
- Surface scaling
- Cracking of the Craze (easily caused due to freeze and freeze cycles)
When the concrete has been colored that day, rain on the day of pour may also wash out the colors, and lead to streaks.
Instead of tearing out the concrete and re-starting over the best option is to take off the thin layer of surface grinding it away and then apply an overlay and after ensuring that the concrete that is underneath is solid and structurally solid.