Foundation undermined - what to do?

An undermined foundation is a real nightmare for every homeowner. Because this leads to settlements that can have far-reaching consequences. Here you can read how to proceed if the foundation has been washed out.

Water - a steady force

The power of water should never be underestimated. Many homeowners make these experiences continuously. It can be particularly fatal if the foundation is undermined. But it is not always clear that the foundation has been undermined.

The undermined foundation

However, settlements are noticeable. In most cases, subsidence breaks out. In addition, a building can always stand diagonally. A typical example, which became famous for that very reason, is the Leaning Tower of Pisa.

In the case of Pisa, it is the soil that does not bear the weight evenly. Even with a foundation on clay soil this can happen. But under-flushing is also becoming more common in Germany in recent years.

Often an increased groundwater level is responsible

Among other things, this has to do with a strongly changed environmental awareness. People today save a lot of drinking water, and there are also machines that are also more economical in terms of water consumption. In addition, more and more communities are banning the construction of land over the public canal. Rather, the drainage should be done via leachate.

This has resulted in a higher groundwater level in many regions. That's hot, even if a foundation is now undermined, there must be no bungling in founding the foundation or creating the hydrogeological soil assessment, as is often assumed.

Various measures for a submerged foundation

But what can be done if the foundation is undermined? There are several techniques that can be used to rebuild a foundation while creating a solid foundation. The two procedures used are named after the companies that established them:

  • URETEK injection
  • ERKA segment piles

Resin injections under the foundation

URETEK injection calculates the exact need to lift the foundation. Accordingly, then holes are made. These holes are used to inject a 2-component resin. Combining the two components, the resin expands similar to PU foam. The building foundation can be raised exactly to the millimeter.

In addition, the resin also compacts the substrate, thus creating a solid foundation. The resin is harmless to the environment and groundwater. The procedure can only be carried out by appropriate specialized companies.

A subsequent deep foundation

The second technique is the ERKA segment piles. These are individual segments, which are connected to each other similar to tongue and groove. The individual segments are relatively short, so that they can be pressed even in a small space.

The further the segments are pressed in, the more subsequent segments are put on. Either the piles are driven so far into the ground until they hit solid ground or the compacted soil below and the lateral frictional resistance provide a firm grip.

Tips & Tricks

Under no circumstances should you wait too long when you notice initial settlements. If the foundation has been washed out, this process is usually still ongoing if you detect the damage. Therefore, appropriate action should be taken immediately in such a case.

Artikelbild: Bastian Kienitz / Shutterstock

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