One of the most common causes of damage to building foundations in Queensland is the failure of the footing system, particularly in areas that have reactive or unstable soils. Investigating in-ground drainage system failures often reveals broken or leaking pipework.

Defective drainage may not be the initial cause of damage to a building’s footing system. However, once in-ground drainage systems are damaged, the resulting leakage of wastewater into reactive soils around the footings of a building is likely to contribute to soil expansion and cause further damage.

Who can prepare a site classification report?

A site classification report must be prepared by a person who holds a site classifier licence issued by the Queensland Building and Construction Commission (QBCC) under the QBCC Act.

Who can prepare an articulation or footing/slab design?

Designs can be prepared by the following qualified people:

• an engineer with formal recognition of qualification and competency registered to practice as a Registered Professional Engineer of Queensland;

• a person who holds a hydraulic services design licence issued by the QBCC under the QBCC Act.

• a person who holds either a trade contractor or nominee supervisor plumbing and or drainage licence issued by the QBCC under the QBCC Act.

Due to the specialised nature of footing designs, it is recommended that practitioners are experienced in this field and are confident in their ability to undertake the work competently.

How much should a soil report cost?

This will depend on the location and access to a site, but generally for a new house or renovation a cost of $500.00 is a reasonable guide. There will be two boreholes drilled to assess the soil quality, and to allow for an engineer to design the footings and slab for your new building works. The relatively low cost for a soil test is certainly worth it to know that your building can withstand any movement in the foundations holding it up.