I completely trust our builder. He did explain. I was exploring if anyone had anything to say one way or the other. It’s like when your mother tells you you have a cold but the Dr tells you you do not. I trust, but wanted to verify.

Every fall and winter there is a thread on this in this forum.

Oh, I should have searched!

Have to figure out how to do that lol

https://www.houzz.com/discussions/query/Foundation-in-winter

No worries. Its up there with the late winter threads on "omg theres mold!!!1!" You'll find one of mine there.

I'll repeat myself.

But add the caution that calcium chloride is not riskproof. And, in fact, is prohibited in certain conditions. Instead, I've always used heated aggregate and lots of insulation instead. You might want to speak with your structural engineer or the building inspectors in your jurisdiction.

How did everything end up for your build? Above I was provided a link that lead me to many more on how safe it is to pour foundation in winter.

Our last house in the Chicago area--foundation dug and poured in February.

Any concrete specification should prohibit pouring concrete on frozen ground. When the ground thaws the foundation will settle; how much depends on the nature of the soil. Perhaps the custom builder is thinking of a little frost on the ground. Listen to your FIW.

But cold weather shouldn't stop you from building in the winter. If you think the ground will freeze after excavation, cover it with straw bales (not hay).

Well in my location we aren’t taking about 3ft of permafrost. In a cold winter it might be 6inches of frozen ground.

Don't gamble on the acceptable depth of frozen ground.

The 2015 IRC R403.1.5 says: Footings shall not bear on frozen soil unless the frozen condition is permanent.

For an even better reference download 306R-16 Guide to Cold Weather Concreting. My older copy says concrete should not be placed on frozen subgrade material.

Thank you

We had the same situation in PA last winter.. decided to wait for the spring rather than deal with pouring, curing and keeping it all warm. So we waited to build until spring. I think March 25th. Of course COVID shut the state down just prior and we didn't actually start until mid-June. Lol. You just never know what will happen with any build! Good Luck!

Doc- who was your builder?

Small one off builder in north central PA :) PM if you want more info

It may be helpful to differentiate the components of a cast-in-place concrete foundation: A concrete footing and a cast-in-place concrete foundation wall. Typically, the foundation wall is constructed on a previously constructed concrete footing.

It is important that the footing not be placed on frozen ground or risk shifting and settling afterwards. I suspect the builder is referring to chemical additives which can be added to the concrete during formulation to lower the freezing point. That affects the concrete, but it doesn't do anything with respect to frozen ground.

Can't you begin excavation earlier?

If only we had thought of that. Lol. Unfortunately no.

Your contractor probably thought you were concerned about concrete freezing before it reached adequate strength.

The temperature of the earth at the footing level should be about the temperature of well water which might be 50 degrees. If you put insulation (like straw bales) on the exposed subgrade, the sub grade should be above freezing when the footings are poured. Its also possible to use electric heating mats

If this is a basement, you should be asking about waterproofing.