Underpinning in Queensland
Strengthen and stabilise failing foundations before damage spreads.
What is Underpinning?
Underpinning is the process of reinforcing an existing foundation to increase its depth or load-bearing capacity. It is commonly required when the original foundation is inadequate, soil conditions have changed, or the structure above has been extended.
Signs You May Need Underpinning
Cracked walls or ceilings
Diagonal or stair-step cracks in brick or plaster often signal foundation movement that underpinning can stop.
Sloping or uneven floors
When floors dip or feel springy underfoot, the foundation beneath may be settling unevenly.
Doors and windows sticking
Frames that no longer sit square are a classic sign of foundation subsidence requiring attention.
Soil movement or erosion
Queensland's expansive clays and seasonal flooding can cause soil to shift under slabs and footings.
How Underpinning Works
Inspection & Assessment
A specialist inspects the foundation, reviews soil conditions, and determines the cause and extent of movement.
Method Selection
Options include mass concrete underpinning, screw piling, or resin injection depending on the site conditions.
Staged Excavation
Work proceeds in small sections to avoid overloading the structure, with each section poured and cured before the next.
Final Inspection
The completed work is checked for level, load transfer, and compliance with building codes.
Frequently Asked Questions
How much does underpinning cost in Queensland?
Costs vary widely depending on the size of the property, foundation type, and extent of damage. Most residential jobs range from $5,000 to $30,000. Always get at least two written quotes.
Do I need a building permit for underpinning?
Yes. Underpinning is structural work and requires a building permit in Queensland. Your contractor should handle the application through QBCC-compliant processes.
How long does underpinning take?
A typical residential underpinning job takes 3–10 days depending on the number of sections to be treated and curing time.
Can I stay in my home during underpinning?
In most cases yes, though there will be noise and limited access to parts of the property. Your contractor will advise based on the specific scope of work.