Solutions

Start with the mechanism, not a predetermined method.

Similar visible symptoms can result from different conditions. Investigation should establish what is moving, where support has changed and which constraints govern the response before a treatment pathway is selected.

Decision framework

From observed condition to controlled intervention

01Define the symptom Record the location, extent, progression and operational consequence of cracking, differential movement, rocking slabs, surface deformation or suspected voiding.
02Review the context Consider asset geometry, loads, construction records, ground information, drainage, services, previous repairs and changes in use.
03Test the working hypothesis Select appropriate investigation and monitoring methods, recognising the limits of each method and where direct verification is needed.
04Design controls and acceptance criteria Define treatment zones, sequencing, monitoring, stop conditions, contingencies and the evidence needed to assess completion.

Potential pathways

Options considered through site-specific design

Deep Injection

Controlled treatment at designed locations and depths may be considered where the investigation identifies a suitable supporting-ground mechanism. Material selection, injection pattern, monitoring and treatment limits require project-specific design.

Slab lifting & void filling

Where a ground-supported slab has lost contact with its support, a designed injection sequence may restore contact or fill accessible void space. Any lifting objective requires survey control, defined tolerances and protection of adjoining elements.

Supplementary foundations

Where loads need to be transferred beyond unsuitable near-surface material, a supplementary support system may be assessed independently or alongside other measures. Load path, connection details and verification remain engineering inputs.

Subsurface diagnosis

Ground-penetrating radar and complementary methods can help investigate interfaces, anomalies and potential voids. Interpretation depends on site conditions and should be correlated with records, observations or direct checks where appropriate.

Selection criteria

Suitability depends on more than access.

A treatment review should consider the diagnosed mechanism, affected depth, load path, ground and groundwater conditions, buried services, structural sensitivity, allowable movement, work area, operating windows and the ability to verify the result.

No pathway should be presented as universally suitable. Where evidence is incomplete or conditions fall outside the design basis, further investigation, an alternative method or a combined response may be required.

See the information needed for an initial assessment →

Verification

Define the evidence before work begins.

Depending on the intervention, the verification plan may include level or movement monitoring, injection records, pressure and volume observations, probing or drilling, load response, visual inspection and agreed post-treatment checks.

The appropriate instruments, criteria and reporting scope must be set for the project. This private page does not state performance, warranty or regulatory outcomes.

Start with the site condition

Bring the symptoms, history and constraints together.

The assessment guide identifies the minimum information needed for a useful preliminary review. Submission remains disabled pending approval of contact and privacy controls.

Prepare an assessment brief