Pouring concrete after cold night

[Surinder85]

Hi,

My builders are set to pour concrete into the foundation dig on Friday, the temperatures may be below zero overnight from Thursday evening, maybe as low as minus 2 degrees celsius.

The daytime temp on Friday midday will be 9 degrees, therefore as a safety measure, is it worth covering the ground area with tarpaulin or will this have minimal effect?

A lot of factors involved in how quick ground can thaw and warm up..so it is just a general question regarding the effectiveness of covering the site.

Thank you

 

[omph]

Hi,

My builders are set to pour concrete into the foundation dig on Friday, the temperatures may be below zero overnight from Thursday evening, maybe as low as minus 2 degrees celsius.

The daytime temp on Friday midday will be 9 degrees, therefore as a safety measure, is it worth covering the ground area with tarpaulin or will this have minimal effect?

A lot of factors involved in how quick ground can thaw and warm up..so it is just a general question regarding the effectiveness of covering the site.

Thank you

It could loose 50% of its 28 day strength if it freezes within the first day. How deep are the foundations ? Covering it can help but will have limited results. Also, weather station temps may not reflect your actual temp, it could be colder or warmer on-site. You can use gas blowers to heat trenches before pour.

You could mitigate subsequent issues by using additives to accelerate setting, using hot water in the mix, erect a tent over it, and run a propane gas blower overnight at lowest speed to keep the temps up. It's a lot of work and will cost a lot more, and your builders probably just want to get it over and done with as soon as.
Ideally, you should delay it till you can get some decent temps, and the job should start as soon as the sun rises (7-9am) to give it enough daytime warmth to set.