I have a 1947 cape (Cape Cod style home) in New England. The basement egress walls which are made of unfilled cinder blocks and run parallel to the house under the porch are caving in. I thus have to have them broken up and have new walls built--of cinder blocks, rebar, and filled with concrete, layer by layer.
Because of the freezing weather, I had thought that I should wait until spring or summer to have this done. However, one person I have spoken to has told me that there is no need to wait for the spring thaw. Because of the headache of the current egress collapsing, I am very wary of anything that could weaken the new walls, and so am uncomfortable with the idea of pouring the concrete for the egress walls in the winter. I have read that it is possible to pour in freezing weather, but the process seems rather elaborate and uncertain.
So, my question: Is it generally a bad idea to pour concrete in freezing weather? Should a rebuild such as this be done after the threat of a freeze? As to freezing weather, it's difficult to predict how cold it may get, as it's been a warm winter. It will get as low as 16 degrees F this week during the late night and early morning hours, but in past years has gotten much colder than that, and may this year.