What Does Pre-Construction Soil Test Determine, and How Is It Done for Buildings?

Since soil takes the weight of the entire structure, testing it is the first and essential step of pre-construction. This specific test is primarily performed to test the bearing capacity of the soil. Moreover, an appropriate soil test shows the coil’s physical and chemical composition. Failure to adequately test soil can lead to critical safety and financial risks. Therefore, it’s crucial to do soil testing to understand the soil properties and use the acquired information correctly in planning and designing the construction project. This article informs what soil test determines and how it’s done for buildings.

What is Determined by the Pre-Construction Soil Testing?

The pre-construction soil testing can help professional contractors determine the following:

  • Suitable construction techniques and possible foundation issues based on the soil test results.
  • The depth and length of the pillars are to be inserted into the soil for laying the foundation of the building.
  •   The choice of construction material is also greatly affected by the soil’s chemical and mineral composition.
  •   Specifies the soil reactivity, which informs how soil will react to certain conditions on-site, like whether it contracts, expands, or moves.
  •   Identify soil liquefaction and the requirement of soil stabilization.

How is Soil Testing Done Before Constructing the Building?

A pre-construction soil test determines the soil’s suitability for building foundations. Here mentioned are the basic steps involved in the soil testing for the building construction:

Determining the Test Pits’ Location and Depth

The first important step a professional performs is identifying the location and depth of the test pits. Digging the test pit where the foundation will be constructed is a must. In addition, the test pit’s depth must be at least equal to the foundation’s depth.

Digging the Test Pits

The contractors dig test pits using a mechanical excavator or hand tools. Dig the test pit large enough for proper soil sampling and testing.

Collecting Soil Samples

Take a soil sampler and collect soil samples from different depths in the test pits. Building size and soil conditions are two factors that determine the number of samples. According to professionals, taking at least three samples at each depth is essential.

Testing the Soil Samples

Once soil samples are collected, test them for various properties of soil, such as soil texture, density, moisture content, shear strength, and permeability. Such tests can be conducted on-site or laboratory using portable equipment.

Analyze the Results

After conducting the tests, professionals analyze them to determine the soil properties and suitability for pre-specified foundation design. The foundation design might need to be modified based on the results.


Appropriate soil tests can help an individual save a lot in laying a solid building foundation. It’s important to note that the soil test for buildings must be conducted by qualified and trained geotechnical engineers or soil testing professionals. They will have the knowledge and expertise to perform the soil test and accurately interpret the results. Moreover, these professionals can guide architectures to design safe and reliable foundations for the building.

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