GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

slab on grade in winter

arnoldk | Posted in General Questions on


Due to endless delays to obtain my building permit, we were schedule to pour the 18-20 inches footing with the slab on grade in October but now it won’t happen until early January 2022.

I live in Ottawa, Canada and I am wondering if anyone has experience having their slab poured in the winter? I am wondering if it’s worth the extra risk and cost in order start this build and try to make up time.

Thank you,

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. plumb_bob | | #1

    It will be more difficult and expensive, period. Access, snow clearing, thawing frozen ground, admixtures added to the concrete, insulating after the pour etc. etc.

    Not just the foundation work will be slower, but excavation for services, plumbing, framing will all be slowed by winter weather.

    If you can hold off until spring the project will progress in a more efficient manner.

  2. Expert Member


    I'm with plumb-bob. The possibilities that real problems will occur are high. Leave it until spring.

  3. arnoldk | | #3

    Thank you both for your point of view. We have been starting to lean that way and I am not sure how much I want to be framing in February at -10 to -25*C.

    Thank you,

  4. Expert Member
    BILL WICHERS | | #4

    Another vote here for waiting until spring. I have a similar project at work right now (a large generator pad for a commercial building), and it will soon be too cold for tenting alone to allow regular concrete mixes to cure. The low temperature concrete additives/mixes all have downsides, so I’d avoid using them unless you have no choice.

    The general rule is to only pour concrete in the winter if you absolutely have to. The same goes for excavation work. In the utility world we stop boring underground conduits too, since we have to excavate (“daylight”) around other utilities at every crossing and we have to “dig” with steam ($$!!)


    1. arnoldk | | #5

      Thanks Bill. We are going to delay the house built until spring as much as that suck.

      My wife is still considering doing just the detached garage so we can make some progress but I'm not sure it's worth the extra cost and the headaches of having to pamper the site before and afte0r the concrete pour.


Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |