ᐅ Constructing the foundation slab before winter

Hello,
we planned to build the foundation slab for our single-family house this year.
And next year, as soon as the weather allows, to start building the walls.
A friend of mine said that the foundation slab can heave and settle during frost if there is no upper floor on top of it, making it unusable.
Is that true? What percentage of cases does this happen?
Or is there a way to prevent this?

Thank you very much for your help.

Rising or settling only occur if the ground has not been constructed frost-proof. It would be problematic if all concrete surfaces had to be covered with buildings just to prevent movement…

The frost-proof construction must reach down to the frost depth specified by the German climate map. This ranges between 60 and 120 cm (24 and 47 inches).

By the way, there was a recent thread about concreting during frost risk:

https://www.hausbau-forum.de/threads/bodenplatte-noch-dieses-jahr-moeglich.8911/

Best regards

Hawk-14 schrieb:
...A friend of mine said...

What qualifications does this friend have? Is he an authorized party contractually involved in the construction? What legally reliable information do you expect from anonymous advisors without any guarantee, warranty, or formal training?

Best regards

Hello €uro,

The acquaintance is the site manager. However, he mentioned that if the construction company responsible for the foundation slab provides a written warranty, it would be feasible.

During the quotation discussions with various construction companies, I always said we planned to do the foundation slab this year and start building the walls next spring. However, no one mentioned that something like this could happen.

We don’t have a critical schedule; it would just have been nice to start this year since I still have a lot of remaining vacation time. Of course, if everyone says it doesn’t make sense or the risk is too high, we will postpone it until next year.

klblb schrieb:
Earthworks including the foundation slab take 1 week, but then you have to protect the slab all winter and especially secure the construction site? We could also quickly do the foundation slab before winter, but we prefer to use the winter months to refine the planning, compare offers more thoroughly, etc. And the risk of interest on interim financing doesn’t arise because the financing will be finalized later (in spring).

That’s exactly right. Now is really the time to decide whether to install the heating before winter or not; you can save some time there, but no masonry work will be done anyway.

Once the house is finished, it won’t matter whether it was completed 1 or 3 months earlier... the main thing is having the house.

Use the time to plan everything carefully or to finalize selections. When construction is underway, things can get really tight, and you might have to make rushed decisions.