Pouring Concrete In Bad Weather

When you need to pour concrete outside, there are perfect weather conditions that help you get the best results – and warm and dry is nearly always the best combination!

Unfortunately, if there’s one thing you can’t rely on, it’s the British weather. And just as importantly, with schedules to stick to and deadlines to meet, you can’t always afford to wait until the weather improves, especially if it looks like it’s set in for a long period.

So what do you do when you need to get on with your project, but the only way you can do so is in conditions you really shouldn’t and would prefer not to?

This month, the team at Stewart Brothers Concrete is investigating the best way of pouring concrete when you have to do it in bad weather.

POURING CONCRETE IN THE RAIN

Getting the right mix of cement, aggregates and water for a particular project is an art and essential for its long-term success. So the last thing you want is the weather trying to add further water while you’re trying to pour. Heavy rain at the wrong time can seriously affect the strength of the concrete if it goes into the mix, or can result in an uneven surface if it lands on freshly poured concrete. 

When it rains before a pour, you should always avoid pouring the concrete onto a wet surface or into wet footings or foundations, so a site with good drainage is essential. It’s also worth taking the time to check that there are no gutters or downpipes that might start discharging water onto the site.

If it looks like there may be rain during or after your pour, and delaying isn’t an option, be prepared to cover the site with waterproof sheets or even create a temporary shelter. 

If you get caught out by a sudden unexpected shower, act as quickly as you can to make sure that any surface water is cleared and then cover the area with waterproof sheets or tarpaulins.

POURING CONCRETE IN COLD WEATHER

Cold weather presents different problems to rain, because freshly poured concrete can be rendered unfit for purpose if subject to temperatures below freezing point. That’s because the water in the concrete can freeze and then expand, potentially cracking the concrete as it does so.

You really need to keep the concrete at a temperature of at least 5ºC for the first 48 hours after pouring – after this, it should be strong enough to resist the potential for damage from cold temperatures. If it drops any lower than 5ºC in that initial period, it will take longer to develop the necessary strength to resist the dangers of frost.

If your site is likely to be exposed to minor frost at night, you can protect it by covering the pour with frost blankets and insulation. Again, a temporary shelter could be advisable to stop cold winds reaching the new concrete.

If severe frost is expected, it may be possible to get your concrete supplier to supply the concrete ready heated – if that is not possible, you should delay pouring until the ambient temperature rises to more than 2ºC.

Finally, you should also avoid pouring concrete onto frozen ground. If you’re working during a cold snap in winter, prepare in advance by protecting the site for a few days ahead of the pour.

Make your construction project more straightforward by sourcing your concrete from Stewart Brothers Concrete. Experienced at working in all weathers, our expert team can provide top-quality concrete to sites right across Kent and has the knowledge to ensure a perfect finish every time.

Get in touch with us now to find out more or to order a delivery.

For more information on Pouring Concrete In Bad Weather talk to Stewart Brothers Concrete