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Sinkhole repair

Sinkhole repair and prevention

Sinkhole repair addresses the damage incurred when soil and structures collapse into an underground void. It also comprises preventative measures to help avoid more problems in the future.

Mainmark’s ground improvement technologies provide swift, reliable and cost-effective sinkhole repair and prevention. Suitable for a wide range of applications from factories and warehouses to offices and social housing, our sinkhole repair solutions help to restore the stability and integrity of the ground beneath commercial properties, roads, railways, airport runways and industrial buildings.

Depending on project requirements, we can offer Teretek® resin injection, JOG computer-controlled grouting and Terefil® lightweight cellular concrete. All these advanced sinkhole repair methods:

  • Fill voids
  • Improve ground
  • Increase the load-bearing capacity of the ground
  • Lift and re-level structures suffering from subsidence caused by sinkholes

These non-invasive sinkhole repair and prevention solutions are carried out with surgical-like precision. Small holes are drilled into the ground or under foundations, and the relevant materials are injected into precise locations. There is minimal disruption to building occupants, public or operations, and surfaces can be walked or driven on immediately after work is completed.

When is sinkhole repair needed?

Sinkholes are a type of subsidence and can pose significant risks to property and people. While sinkholes may seem to appear suddenly, there are often warning signs, such as:

  • Depressions or potholes – These can vary in size and depth and may appear suddenly or over time.
  • Cracks in the walls, ceiling, floor or ground – New or unexplained cracks, especially if they are wider than 3mm.
  • Doors and windows not opening or closing properly – Particularly if they were previously functioning correctly.
  • Leaning trees, posts or walls – If previously vertical structures start to lean, it could be a sign of subsidence or a developing sinkhole.
  • Vegetation changes – If the health or appearance of outdoor plants changes for no apparent reason, it could indicate that soil and groundwater conditions have changed due to a sinkhole.
  • Pond formation – The abrupt formation of a pond or standing water may signify the development of a sinkhole.

If any of these warning signs are observed, it’s crucial to take them seriously and seek out professional sinkhole repair services right away. Early detection and intervention can help prevent damage to buildings and building contents, while also mitigating safety risks.


Sinkhole repair technologies

Mainmark sinkhole repair technologies

Teretek® – Resin injection for sinkhole repair

Teretek® is an engineered solution suitable for sinkhole repair; it utilises a plural component, expanding polyurethane resin. The expansion force of the material results in the controlled lift of structures, with a by-product of localised bearing capacity improvement through soil densification.

Teretek® resin injection technology

JOG computer-controlled grouting for sinkhole repair

JOG computer-controlled grouting uses a multi-point injection technique to insert cementitious grout materials under foundations. It can be used under commercial buildings ranging from single-storey shops to high-rise structures. The injected materials have a controlled set time, which allows for the precise lifting of a structure.

JOG computer-controlled grouting

Terefil® lightweight cellular concrete for sinkhole repair

Terefil® is a technology used to create lightweight, cellular concrete for large void fills, used for sinkhole repairs. Terefil® material densities can range from 500 to 1,500 kg/m3 with strengths ranging from 0.5 to 5 MPa. The material sets within hours of placement, is flowable and self-levelling. Terefil® is routinely used for sinkhole repairs.

Terefil® lightweight cellular concrete

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Mainmark technology benefits

Benefits of Mainmark’s treatments for sinkhole repair


Our sinkhole repair solutions can be completed within a matter of days or hours.

Environmentally inert

We use safe materials that are non-toxic and do not leach into the environment or affect the treated area.


Sinkhole repair can be carried out without the need for excavation or extensive disruption.

Varied density choices

Material density can range from 30 to 1500 kg/m3.

High strength

Our materials can achieve strengths of 50 kPa to more than 20 MPa.

Variable flow properties

With variable set times ranging from seconds to hours, materials can be precisely controlled and pumped over long distances.

Soil stabilisation FAQ’s
What happens with unlevel driveways, floors and hardstand areas?

After the application of the Mainmark solution, unlevel surfaces will become aligned again as the ground underneath is strengthened and re-supported. Simple cosmetic repairs may be required.

Will there be a mess?

Very little, if any. We use Teretek® engineered Resin Injection technology, which is likened to “keyhole surgery”, or JOG Computer-Controlled Grouting, with no major excavation and minimal disruption or mess. The injection holes required are very small.

How long does it take?

Each project is different and depends on the required amount of lift, area for correction, building construction, and ground conditions. Most projects can be completed in a day or two, and we can work at night or on one area at a time, so your business can keep operating.

Do i need to send my workers home?

No, most projects don’t require you to vacate the premises or even move furniture or equipment. For the most part, you can keep operating as normal. Driveways can often be driven on in as little as 30 minutes after treatment.

What warranty will i get?

The materials we use have been developed for use underground and have been specifically engineered to resist shrinkage and deterioration. Teretek® is warranted by Mainmark for an industry-leading period of 50 years.

Is it safe and environmentally friendly?

Injected Teretek® and JOG materials are environmentally inert and have no detrimental effects on the environment.

Get a quote

Arrange a site assessment in 3 simple steps:

Step 1

Submit your enquiry using our online form. Include a brief message about the type of foundation issues you are experiencing.

Step 2

Our friendly customer service team will be in touch to schedule a site assessment that suits you.

Step 3

One of the Mainmark experts will visit your commercial property, assess the damage, and ascertain the likely cause. They will establish the approach needed, creating a plan specific to the needs of your building and provide you with a detailed quote.

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Mainmark Ground Engineering (UK) Ltd.

CRN: 09372443

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