Mainmark explain how a major property refurbishment was able to take place with the minimum disruption thanks to their resin injection solution

A 1930s end-of-terrace traditional double brick house in Oxford was being converted into apartments. An extended kitchen area was subsiding and had several visible cracks where it joined the main house. The property developer wanted to avoid a removal of the extension and was also seeking peace of mind that the building wouldn’t suffer any further structural damage.

The refurbishment first required ground improvement of the soils beneath the foundations to support the additional load that was to be placed on the structure. The remediation needed to raise, re-level, and re-support the strip foundation within the tolerance of the extension.

There were a number of considerations that needed to be factored in, including the confined space the team had to operate in and limited access to the site due to a neighbouring fence.

A unique approach

A resin injection solution was chosen and applied to the foundation soil, which consisted of sand and gravel. The resin injection application aimed to raise the back portion of the property and maximise ground bearing capacity, which would reduce the risk of further subsidence. The resin solution eliminated the need for demolition or invasive excavation, and minimised disruption, noise and mess for the neighbouring properties.

The process in action

Mainmark’s engineered resin injection solution, Teretek, was applied through a total of seven injection locations at depths ranging from directly below to two metres below the foundations. Teretek is a two-in-one engineered resin injection solution that can increase ground bearing capacity while also re-levelling structures, in a process that is likened to keyhole surgery. On entering the ground, the polymer resin solution mixes together and quickly expands, strengthening the soil and re-levelling buildings quickly and efficiently.

The Mainmark team achieved a maximum lift of 12mm at the lowest corner and work was completed in a single day – the fast completion time allowed the property developer to expedite the refurbishment. The solution also gave the developer peace of mind and allowed the property to be let more quickly, therefore realising a return on investment sooner than anticipated.