Help and advice

Why is a soil test needed for project home builders?

What is the importance of a Soil Test?

Soil testing is mandatory and is crucially important in getting a true fixed price. You should never sign a contract with a builder until you have this testing completed as the results can significantly affect your expected costs.

Soils vary in type, composition and strength. When building a new home this will determine which slab is necessary specific to your site and specific to the home you want to build. It will also assist in understanding the type and number of piers that will be required for the foundations of your home.

A soil test is conducted by a geotechnical engineer providing an independent assessment of your soil. The test will measure the amount of reactivity on your site – that is how much is it likely to move, contract or expand due to changing environmental conditions and moisture content. In broad terms the classifications A-P can be defined as:

  • Stable, non-reactive which is characterised by rock or sand that has little if any movement.
  • Slightly, moderately, highly and extremely reactive sites due to chemical composition and moisture content in the soil.

The variation in cost of different slabs specific to soil reactivity can be significant. Some soils are very strong and can support significant weight, while other soils are weak and compress under light loads.

The goal is simply to provide the right slab type that will ensure that your double or single storey home is stable under all conditions and not be subject to movement as conditions change.

Whilst conducting the soil test, ANSA Homes will also have an independent soil impact test performed to check the strength of the soil. This provides additional evidenced on the type and number of piers required to support your slab and your home.

ANSA Homes views both these tests as critical to giving you a fixed price quotation. By engaging the same independent engineers for both the soil & impact tests ANSA alleviates the risk to you with the assessment accountability on the engineers.