These houses have a timber frame and a single brick veneer on the outside and brick piers around the perimeter to support the perimeter frame, internal walls and floors are supported by stumps.
Timber Stumps and Sinking Soil
Early brick veneer houses may have timber stumps, and if they are failing they then need to be replaced.
Most later brick veneers have concrete stumps, but most of the problem with this type of house is that it sinks in the middle due to the soil shrinking because of lack of moisture, drought and reactive clay soils.
As the ground dries out the concrete pad and the concrete stump sinks into the ground, sometimes leaving a gap on top of the stump.
Evidence of this can be seen inside the house with cracks appearing in the plaster, doors jamming and gaps under the walls.
Fixing the Problem
This can be rectified by setting the house on jacks and lifting back to its original position, and packing the existing concrete stumps.