Don't just fill the void.
Fix what made it.

Because the resin fills the void but doesn’t address what created it. If a leaking stormwater pipe is still washing soil away beneath the slab, the resin you injected is sitting in stable position — but new voids are forming beside it. Within 12 to 36 months, the same symptoms reappear. This is why our Pathway 03 includes drain repair: it eliminates the recurrence mechanism.

Three factors decide it: the depth and shape of the void, the cause, and the structural load involved. Resin is excellent for shallow voids in stable soil with localised settlement — fast, clean, minimal disruption. Traditional concrete underpinning is better when the footing itself has rotated, the soil bearing capacity is permanently compromised, or council consent requires a structurally-engineered solution. We assess both options on every site visit and recommend honestly. Single-method providers structurally can’t do this.

Three pathway floors: $3,500 + GST (localised), $7,500 + GST (foundation involvement), $14,500 + GST (combined diagnostic + drain + resin). A site assessment confirms which pathway fits your situation. We don’t quote in $2,000–$10,000 ranges that leave you guessing — we give you the floor, then refine to a precise number after the site visit. The site assessment fee is credited to the works if you proceed.

For Pathway 01 and most Pathway 02 work, no — you stay in the home. Resin injection uses 16mm access holes, cures in minutes, and the area is usable immediately. For Pathway 03 where drain repair is involved, there will be excavation in the affected zone of the property (typically a side or rear strip), but the house remains habitable. Total disruption is usually one to seven days depending on pathway.

Three layers. The polyurethane resin itself carries a 50-year product warranty from the manufacturer (Geofix-supplied). Our workmanship warranty is 2 years across all pathways. If your project includes drain repair under Pathway 03, the drainage section carries a separate workmanship warranty. We coordinate all three under one project file so you have a single accountable point of contact.

Generally no for Pathway 01 and many Pathway 02 jobs — non-invasive resin injection beneath an existing slab usually falls outside Building Act consent requirements. Pathway 03 work that includes drain repair may require approval if the drainage scope is significant. We handle the council application process when it’s needed, and we’ll tell you upfront in the site assessment whether your job needs it.

It depends on the cause. Sudden events — a burst pipe, an earthquake event, a storm-driven washout — are often covered. Gradual subsidence from long-term clay shrinkage or poor original compaction usually is not. We can supply the diagnostic report and cause attribution your insurer will need to make a determination. Always check policy wording before assuming coverage.