Hot & cold weather
Sourced answers on hot & cold weather, written for the person standing in front of the problem.
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1
How cold can you pour concrete?
Below 40 °F for three straight days, ACI 306 cold-weather protection applies. Fresh concrete freezes near 25 °F, and freezing before 500 psi is permanent.
2Can you lay concrete in the rain?
You can, but the surface has to stay protected. Rainwater worked into fresh concrete raises the water-cement ratio and leaves a weak, dusting top layer.
3Can I lay concrete in cold weather?
Yes, with heated mix water, unfrozen ground, blankets staged before delivery and a longer protection period. What suppliers do, and when to wait for spring.