If you have a building project coming up but the weather looks abysmal, you’re probably wondering whether you’re going to have to call off the concrete pouring. Well, in an ideal world, you certainly wouldn’t pour concrete in the rain, but it is possible if you’re really in a pinch. Let’s take a look.
The problem with pouring concrete in the rain
As you well know, water is a key ingredient of concrete, the other two being cement and aggregates. To create the perfect concrete mix for any particular job, you need to get the quantities of these ingredients just right. As you can imagine, then, if it’s raining on the day that you decide to pour your concrete, if you don’t do anything differently, then your concrete will take on some additional water, which will ultimately compromise the strength of the concrete once it has set.
Tips on how to pour concrete in the rain
Given that adding any additional water to your mix is something that you want to avoid at all costs, the main thing that you want to keep in mind is to keep your concrete covered.
Here are the tips:
- If you’ve had a look at the forecast and it’s not looking pretty, make sure that you cover the pour site completely with tarpaulin or plastic sheeting. This is very important, so make sure you take extra care to ensure that everything is covered.
- If you are pouring concrete after there’s been a heavy downpour, make sure that you push any surface water off the slab once you’ve carefully removed the plastic sheeting. There’s no point rushing this bit, because if any water gets into the pour site, it will have been for nothing!
- If rain comes out of nowhere during your pour, the best thing you can do is try and construct some sort of shelter out of timber and plastic sheets. Have these things available, even if the chance for rain is looking low.
- If the rain came and there’s now water-filled cavities or very wet surfaces on your pour site, the best thing to do is hold off on the pour and wait for the site to dry. If you risk it and carry out the pour anyway, there’s a good chance that the concrete will absorb all of the moisture and become compromised. This just means you will have to do it again down the line anyway!
How long after a pour is it safe for rain exposure?
Ideally, you wouldn’t want your concrete to be exposed to rain for at least four hours, but if you want to be safe, wait around eight hours, as this will allow the concrete enough time to become hard enough to be walked on and ensure that the effects of any rain will be minimal to none.
EasyMix is London’s favourite concrete supplier. We’ve been supplying ready mix and volumetric concrete to companies throughout the capital for years, so you can be sure you’re in safe hands with us. Whether you need some concrete for a home project or you have a commercial job coming up that you need a hand with, just give us a call and a member of our team will happily assist.