What Type of Soil Should You Build On?
Soil is the framework for the stability of any land-based construction. It is incredibly important that any constructor is aware of its properties to enable them to design the safest and cost-efficient foundation. There is a huge variety of different soil strengths which makes every build slightly unique. Buildings require strong soils because loose or weak soils can cause the house to sink. Other problems such as separating and tipping can occur.
How is Soil Foundation Strength Determined?
The strength of the soil foundation is strongly related to its physical properties. Quite simply; the stronger the structure of the soil the greater its stability. One of the most common types of soil to build on is clay due to its strong intermolecular forces that make it compact. Particulate containing soils also have extremely good stability. The pore sizes help to bind the soil to particulates creating an inherently stronger base. Stable soils require resilience to rainfall. The soil needs to be able to absorb the water without losing it compactness otherwise the house can be easily washed away or it could sink into the ground. Kaolinite soils have high resistance to wetting and drying cycle so sites, where they are present, are good for building. However, some clay minerals from the smectite group change shape during shifts between dry and wet weather and so should be avoided.
How do you Test Soil Composition?
Testing the soil that you are building on is an important part of the foundation building process. Soil can be tested using a variety of different tests. Litmus paper can be used to determine the alkalinity or acidity of the soil. Spectroscopy can also be used to help indicate what functional groups are present and at what quantity. However, if you don’t have access to high-level equipment simple flame tests can be used as well as color changes to the solution upon the addition of specific chemicals. For example adding sodium hydroxide to a solution containing copper sulfate will cause a blue precipitate to form. Before you start checking up on your GCSE chemistry notes it might be far simpler to check the soil maps that the council might have for your area.
Whilst this video is mainly aimed at gardeners it is extremely useful for helping you in identifying your soil type: