Frost apron for the bottom plate


Frost aprons for the floor slab are always necessary if the floor slab is to be built on certain floors. What this frost apron looks like and what you have to keep in mind will be explained in the following article.

On which floors do frost aprons have to be built for the floor slab?

Basically, these are all frost-sensitive floors. They could cause damage to the house by freezing at the edge of the floor plate exposed to frost.

For which types of soil is there a risk of frost?

Particularly susceptible to frost are:

  • silt
  • volume
  • Sands and gravels, which are very fine-grained

Frost apron for the bottom plate: plate

Even with some other types of soil may be due to the soil composition may risk of frost.

How can it be determined if there is a risk of frost?

This requires a geotechnical assessment in order to be able to determine exactly to what extent a soil holds a risk of frost and thus the risk of possible damage to the floor slab. This is also not a requirement, but recommended from a static point of view before building a house.

How is an ice apron made?

The frost apron usually extends to at least 80 cm below the final ground level. It is - like the bottom plate - made of reinforced concrete. Alternatively, it can also be done as a so-called ballast packing, especially in passive houses and houses with high insulation value.

Change in the static through the frost apron

When setting up a frost apron, it must be taken into account that it may have a very significant influence on the bearing behavior of the floor slab. It must therefore already be taken into account in the planning of the building in order to be able to distribute the bed according to the changed settlement behavior appropriately.

Planning the frost apron

The planning of the frost apron is done by the architect through the blueprints. A previously performed soil mechanical examination is advisable in any case, since the values ​​determined in it are important for static planning.


Video Board: Foundation frost heaving