Teretek® Re-levels and Supports Home Built on Sloping, Unstable Soil

When a local investor purchased a two-storey home with the intention to renovate, the property was identified as experiencing severe subsidence. It had been constructed on a sloping site and the reclaimed ‘made’ ground had caused the home’s foundations to shift, most likely due to inadequate fill material or poor compaction. The structure stood on 1.5m deep strip footings and a suspended, reinforced concrete floor slab. Half of the home had subsided approximately 40mm, causing the wall of the house to separate from the foundation by approximately 20mm. Large cracks also began to form in the walls. The homeowner contracted Mainmark to help fix the issue by lifting the property back to level.

The project was to be completed within three days, without causing disruption to other trades carrying out ongoing renovation works on site. Access to the neighbouring property, via a narrow, shared driveway, needed to be maintained throughout the process.

This noninvasive, environmentally-inert solution successfully returned the house to level and closed the cracks. Teretek’s unique formulation is fast-acting and costs a fraction of traditional underpinning and ground engineering methods. Mainmark was able to apply Teretek® while other renovation work was being completed, which was a great outcome for the homeowner who was able to maintain his schedule of works.

Teretek is a non-invasive ground improvement solution, likened to key-hole surgery, backed up by a 20-year product warranty. It increases ground bearing capacity, fills voids, and can mitigate soil liquefaction, all at a fraction of the cost of traditional underpinning and ground engineering methods, and with no detrimental effects on the environment. The ground improvement at the site was validated by a series of pre- and post-injection dynamic probing tests using a Dynamic Penetrometer system. Trained technicians established the average ground improvement delivered in the treatment zone by comparing pre-probing values to the post-probing values. The testing tool is a small, lightweight piece of equipment that can be used on sites that are inaccessible to other larger machinery. CCTV was used to carry out before and after pipe surveys to check the integrity of the existing drainage pipes and confirmed they were undamaged. The work was completed in 2 days. The client was pleased with the outcome, as well as the efficiency of the project delivery and its cost effectiveness. The homeowner commented, “I would like to thank you and your team for your very hard work last week, in the most atrocious weather conditions, to get the job done.”