Every new building, extension, or development project in Australia requires a soil test and site classification before construction begins. This requirement was introduced in the early 1990s in response to widespread foundation failures and cracked homes.
The Core Purpose
The primary purpose of a soil test is to determine the soil’s reactivity — how much it will expand when wet and shrink when dry. This movement exerts significant force on concrete slabs and footings, and without knowing the soil type, a safe foundation cannot be designed.
The AS 2870 Standard
Our investigation results in a site classification under Australian Standard AS 2870. The site is assigned a class:
- Class A, S, or M: Non-reactive to moderately reactive soils.
- Class H1 or H2: Highly reactive soils requiring stronger foundations.
- Class E: Extremely reactive soils.
- Class P: Problem sites (due to fill, soft soil, trees, or poor drainage) requiring custom engineering.
Protecting Your Investment
Without a soil test, an engineer would have to guess the foundation requirements. Guessing low leads to cracked walls and structural failure. Guessing high leads to massively over-engineered slabs that cost thousands of dollars more than necessary. A soil test provides the exact data needed for a safe, cost-effective design — and is a mandatory requirement for your building approval.