i have seen several new homes basement footings and wall going up in my area lately, even with temps well below freezing and in single numbers. however, whomever my general in having do my flatwork seems to be extremely cautious about doing my basement floor. i dont know too much about flatwork, but anyone care to provide a quick lesson of concrete and temperatures?
Of course concrete puts out heat as it is setting up. We would generally try to blanket the area the day before and try to get some of the 56 degree ground temp to the surface and trapped under the blankets. On residental we were allowed to use calcium, 1 or 2 %, which would make the reaction faster, making more heat, and reducing the cure time. Pouring and waiting for the mud to set a little so it could be finished was probably the biggest problem, sometimes finishing with lights. And then waiting until the slab is hard enough to walk so it could be blanketed.<P>
Generally if it was 20 degrees and rising with the Colorado sun on the slab, and expected overnight lows higher than about 12 degrees we would pour. Sometimes we had to tear the slabs out but that could also happen if it was too hot and dry. HS>
you can place concrete in freezing temps all that is required is that the area temp be brought up to satisfactory levels.Its best to use industrial or simple electric heating pads heaters .Just the same Im in los angeles if weather is too hot we must keep cool with moist burlap and poly sheet to lock in moisture or we spray water on it repeatedly throughout the day for minutes at a time.after placing the concrete you want to keep levels at about 60 degrees as already said