In order to avoid a “leaning tower of Pisa” type structure in the city of Mandurah, we were required to have our soil tested.
For the pretty price of $2860 a Geotechnical Engineer visited our block, made a few holes and wrote a report about what was in them. They found sand, silty sand, clayey sand and more sand.
They classified our land foundation as “P”. According to Australian Standards, “P” includes soft or unstable foundations. (I’ll spare you the full definition.) Foundations classified as “P” can be upgraded to the equivalent of “S” by removing “unsuitable materials” and replacing them with “engineer-controlled sand fill materials”.
Here’s how I interpret their recommendations:
- Remove top soil.
- Compact excavated surface.
- Geotechnical office to reinspect and approve.
- Fill with sand.
- Compact again.
- Reinspect and approve again.
- Build beautiful house that will stay upright for many years to come.