Question 1

When do I need a building permit for a retaining wall in SA?

Accepted Answer

In South Australia, a development application is required for retaining walls over 1 metre in height. Walls up to 1 metre do not require a permit in most zones, but must still comply with setback and drainage requirements. Kenset Construction prepares the documentation and liaises with council on your behalf.

Question 2

What is the strongest material for a retaining wall in Adelaide?

Accepted Answer

Poured concrete and concrete block (besser block) are the strongest and most durable retaining wall materials for Adelaide conditions. They handle reactive clay soils, heavy earthworks pressure, and Adelaide's temperature swings better than timber or railway sleepers, which decay and can fail within 10–15 years.

Question 3

How long does a concrete retaining wall last?

Accepted Answer

A well-engineered concrete retaining wall typically lasts 50+ years with minimal maintenance. The key factors are correct engineering (tie-backs or deadman anchors for walls over 600mm), adequate drainage behind the wall to prevent hydrostatic pressure, and using a minimum 25 MPa concrete mix.