Errors in the Analysis of Soil Test Results

Hydrostop expert Marek Mularczyk discusses common errors in analyzing soil test results

One of the fundamental mistakes in soil test analysis is failing to determine how soil distribution can influence capillary water rise. Even if you have sand around your house, keep in mind that silty sand can draw water up to 200 cm.

Another recurring mistake is insufficient verification of how impermeable soil layers are distributed. Sometimes, a basin-like formation of clayey soils can develop beneath a house. This formation, especially during summer, can fill with meltwater and flood an inadequately insulated building.

These are the results of a survey from one of the construction projects we participated in.
The illustration clearly demonstrates how easy it is to make mistakes when designing waterproofing.

The area marked as the building’s foundation level is within the green zone, where the soil is permeable, consisting of sand, with no detected groundwater or risk of any aggressive environmental factors.

However, take a closer look at the illustration. Surrounding the green "bowl," we see soil layers marked in red, brown, and yellow—these are clay and silt soils, which are impermeable layers.

Now you can see that a soil basin has formed, which will fill with water during spring thaws. The groundwater level will rise and eventually reach our foundations.

Why didn't we detect water during the drilling? Because the tests were conducted during a dry summer.

This might seem like a minor change and a small error, but over time, it could become a costly mistake.

HYDROSTOP Technology