Major Slab Subsidence Remediation

13 Apr

Case Study
Location: Bordertown, South Australia
Project Type: Subsidence remediation
Project Team: Urathane Solutions, Victoria

Project Overview

This project involved a two-storey residential dwelling that exhibited clear evidence of a water leak and associated structural movement. Engineering assessment confirmed significant subsidence across the entire slab, resulting in major structural compromise. The extent of movement led to the property being deemed a total loss, with insurance ultimately paying out after a prolonged assessment and claims process. The occupants were required to vacate the home prior to remediation works commencing.

Key Challenges

Widespread subsidence across the full slab footprint
Maximum recorded deviation of 90mm in the worst-affected zone
Large two-storey structure requiring uniform lift and stabilisation
High-risk wet areas and slab penetrations requiring precise control and deeper injection rods
Voids present beneath the slab due to soil movement

External view of structure affected by subsidence.

Scope of Works

Urathane Solutions undertook a comprehensive stabilisation and re-levelling program, including:

External soil stabilisation and controlled lift
Full internal slab jacking across the entire dwelling
Void filling beneath the slab during re-levelling process

A total of 386 injection rods were installed across the site, including:

- 1.8m rods: 186
- 2.4m rods: 50
- Slab jacking rods: 150

The deeper 2.4m injection rods played a critical role, requiring precise execution to lift the underlying soil, existing pipework, and slab simultaneously, particularly in sensitive wet areas.

*Engineered injection layout plan showing treatment areas and lift targets.*

*Internal slab preparation and injection rod installation.*

Execution & Delivery

Despite the scale and complexity, the project was completed in just two weeks, demonstrating the efficiency of Urathane Solutions’ resin injection technology compared to traditional underpinning methods.

Protection of existing services and pipework
Controlled and uniform lifting across all zones
Minimisation of additional stress on the structure

*Laser monitoring system used to control slab lifting in real-time.*

*Wall tape indicators tracking vertical movement during lifting.*

Outcome

Significant re-levelling achieved across the structure
Structural integrity restored to a serviceable condition
Voids successfully filled, preventing further settlement
A faster and less disruptive customer experience compared to conventional underpinning

The works enabled the property to regain a level of structural normality, transforming what was initially deemed a total loss into a stabilised and recoverable asset.

Urathane Solutions