Underground ground conditions & subsidence – the underlying causes of structural issues

Cracking walls and uneven floors are often symptoms of a structural issue caused by unstable ground conditions or subsidence. To fix these problems, it’s important to understand not only the structural effects on the property but also what is happening in the ground.

Poor understanding of an area’s soil condition can have significant repercussions for a property. For example, the area alongside the River Teign in Devon is characterised by very shallow and well-drained loamy soils over limestone, often on steep slopes. A few years ago, we remediated a residential property that was built on these conditions and subsequently suffered from 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. This eventually caused one of the walls to crack and separate from the foundation by approximately 20mm.[1] This could have been avoided with appropriate measures in place to manage the unstable ground conditions during the building’s construction.

Broadly, there are several soil types that we would encounter when conducting ground remediation. They have different characteristics and therefore different solutions are required. In the UK the most common ground conditions include Clay, Sand, Silt, organic material, and Made Ground.

Clays

A large proportion of London has been built on the aptly named London Clay Formation. Clay soil swells when wet and shrinks when dry causing subsidence in drier conditions, or heave in wetter conditions, particularly after heavy rain and storms. Over-saturated clay also loses its bearing capacity causing building footings to settle in the weakened soil, which can sink even further as it dries out. Clays range from High, Medium or Low Plasticity in direct relation to its shrink-swell capacity.

Sand and Silt

Structures on sand and silt soils often experience settlement caused by flowing ground water, a natural underground watercourse or a leaking sewer or storm water pipe. The finer grains are washed away leaving larger grains to settle, and the building’s footings and foundations become unsupported, compromising the structure above.

Fill / Made Ground

Fill is earthen material placed and compacted in a hole or depression. It can consist of soil, and also includes aggregate, rock or crushed construction waste. Structures built on this type of material are susceptible to the same issues as those on sand and silt, especially when water washes away finer material. Settlement is worse if the fill is poorly compacted.

Organic

Organic soils, especially peat, are weak and highly compressible making them prone to settlement, as the weight of any structure above causes compaction. Primary settlement decreases over time, but can total 100s of millimetres, resulting in significant structural issues.

Often a combination of soils and ground conditions are encountered on the same site. Understanding soils is key to finding an effective, sustainable solution to structural issues, so it’s important to get advice from both structural and geotechnical experts, before deciding on the right remediation plan for your situation.

Mainmark’s Teretek® engineered resin injection solution is used to re-level buildings and remediate issues in foundation ground. It is an ideal solution for all types of soils. For smaller discrete areas typically affected by reactive clay soils, Teretek works well to strengthen building foundations affected by clay soil subsidence. Teretek resin injection is also an effective solution for remediating fill soils, binding the fill to provide extra strength and alleviate the problem of poor compaction. Mainmark’s JOG Computer-Controlled Grouting solution also provides a unique alternative for building level correction and stabilising. JOG is well suited for controlled and precise work, especially on unpredictable sand and silty foundations, and for larger, complex structures.

Both, JOG and Teretek can be applied in situ under existing structures and do not require major excavation works, or manual compaction. Both methods are considerably less invasive than traditional underpinning remedies which require extensive excavation, large quantities of concrete and subsequent backfilling.

[1] https://mainmark.co.uk/wp-content/uploads/2019/02/PP-2017-53UK-Teretek-Re-levels-and-Supports-Home-Built-on-Sloping-Unstable-Soil.pdf

 


By Angelina Varchione

Angelina Varchione is one of Mainmark’s UK Technical Sales Engineer. Graduating with BEng (Hons) Engineering Geology and Geotechnics from University of Portsmouth she has been working in the engineering field for over 10 years.

Introducing Angelina Varchione, Technical Sales Engineer at Mainmark

This International Women’s Day we want to celebrate the diverse talent and expertise of our team at Mainmark by introducing one of our Technical Sales Engineers, Angelina Varchione, BEng (Hons).

At Mainmark, we have an incredible team of experienced professionals, and we pride ourselves on recognising talent and potential. Angelina is a great example of this.

Tell us a bit about your background

I always knew I wanted to work in the engineering and construction sector, so I completed an Engineering Geology and Geotechnics degree at Portsmouth University. Upon completion I worked for a ground investigation company (GEA), and then transitioned to an Account Manager and Technical Sales Engineer for various construction companies. I really enjoyed this type of role and when looking for my next step, Mainmark Ground Engineering was a natural progression.

What does a typical day at work look like for you?

Every day is different, which is what keeps it interesting, with a mix of site and office work. On a typical day I might be visiting residential, commercial, or historical properties to assess if we have a solution for the individual enquiry. Most of the time we do, so I will then do a full site audit, taking the relevant measurements and reviewing access options to enable me to compose a quotation.

Due to the nature of our work, I travel a lot, but I manage my diary so I can arrange to visit several jobs as efficiently as possible, sometimes staying overnight so that I can be most productive. As well as issuing quotes to clients, my job is to answer any questions via phone, email or in person and I also conduct CPD courses.

What’s the most rewarding aspect of your role?

The most rewarding aspect is when a job has been completed and the customer leaves us positive feedback or Google reviews. I share this view with all of my colleagues here, it really is a great feeling and it’s why we do it. Sometimes the customer will also personally get in contact to thank me for the smooth process and great work, and I appreciate the acknowledgement.

What’s the best thing about working in this industry?

We have a strong team at Mainmark with experts in ground engineering and other functional areas, from start to finish, and our customers really benefit from this.

What piece of advice would you give to women or girls who would like to start a career in the engineering industry?

Don’t let the difficulty in buying decent site boots in a small size put you off! In all seriousness, the varied days and mix of different people you will meet makes this a fun and exciting career. See yourself as an asset to the engineering world and don’t restrict your thinking because you are a woman or girl in engineering. Males and females can both make excellent engineers, and it should be your passion, professionalism and expertise that makes you stand out, not your gender.


By Angelina Varchione

Angelina Varchione is one of Mainmark’s UK Technical Sales Engineer. Graduating with BEng (Hons) Engineering Geology and Geotechnics from University of Portsmouth she has been working in the engineering field for over 10 years.

Can removing a tree cause foundation problems and which trees can damage foundations?

There is no denying that trees are a beneficial asset to the environment, our lifestyle and are a symbol of a healthy landscape. They create shade and privacy, contribute to better air quality, provide habitats for wildlife, and help to reduce salinity and soil erosion.

However, without proper consideration and monitoring, trees can also impact our built environment by causing damage to buildings, paths, driveways, and underground infrastructure.

A tree’s influence starts, literally, at the roots; they are responsible for keeping the tree alive by drawing essential nutrients and water from its surroundings. The roots will continue to grow as a tree matures and during this growth, the roots will extend towards anything that will maintain the tree’s life. Roots typically seek out moist soil and will often find entry into old or damaged pipes including sewer drains, sewer pipes and water mains. If a tree is removed from the soil, the foundation will be displaced due to the tree root no longer absorbing water, which could damage a building.

Seasonal change also influences how trees interact with the built environment. During the warmer months of spring and summer, soils can dry out with the lack of moisture causing reactive clays to shrink. In extreme cases, shrinking soil can lead to significant ground movement, subsidence and foundation settlement across the home. Unfortunately, trees can exacerbate this process. In their hunt for moisture, root systems will extend through dried soil, desiccating the ground and absorbing remaining water from the already dry soil. According to insurance company LV, subsidence claims have increased by 49% in the last year, although the rise is in part due to an increase in building surveys, but dry weather in the summer has largely contributed to the spike in claims.

There can be a risk of tree roots causing subsidence. The combination of dry soil and thirsty tree roots is the perfect recipe for ground movement, and the appearance of worrying subsidence symptoms, including cracks in brick walls, distorted timber frames, and doors and windows that jam. Examples of different causes of subsidence around the home, including those triggered by tree roots, can be viewed on Mainmark’s interactive house. Understanding the cause of problems is essential before a viable solution can be found.

Assessing the influence of trees

There are several factors to consider when determining whether trees could be the ‘root cause’ of damage to a home. These include:

Groupings

When trees are planted closely together, they are forced to compete for moisture and nutrients in the same area of soil. The larger the group of trees, the greater the impact on soil drying out in the surrounding area. It is therefore more likely for homes or buildings located near large groups of trees to experience effects of adverse ground conditions as the trees absorb more moisture which can contribute to greater ground movement.

Distance

As a guide, the ‘tree-to-damage distance’ set out by Cutler & Richardson (1989)[1] can be used to determine the probability of damage caused by a tree to built structures based on their distance from it. For example, the furthest distance recorded of a Willow tree damaging the foundations of a building is 40 metres, so it can be assumed that planting this type of tree 50 metres away should be a safe distance. However, you should always consult an expert if you are unsure.

Tree types

Tree activity varies across the year depending on its type, so it’s important to identify the trees that are growing near your home to know how susceptible to damage a building’s foundation is depending on the tree. Deciduous trees, for example, hibernate in winter and re-grow in spring. This lifecycle means their water demand is often highest during drier months, which has the effect of increasing the magnitude of soil shrinkage.

Characteristics

A tree’s physical characteristics can determine how much moisture its root system is likely to absorb, but it’s not always just in relation to its overall size. Research into a tree’s influence on ground conditions has indicated that it is the leaf area of the tree rather than its height that ultimately determines its moisture demand[1]. Therefore, thick or tall trees aren’t always the culprit for dry soil; it’s the amount of foliage that can indicate how much water a tree needs to sustain itself.

Surrounding environment

Roads, pavements, and larger scale developments with limited green space can also prevent moisture from reaching the soil underneath. This lack of permeability can cause dry soil conditions and may force tree roots to draw on the limited moisture available, intensifying soil shrinkage and ground movement. This is common in city areas where trees are planted for aesthetic or ‘greenscaping’ purposes, without considering the degree of exposed soil and abundance of moisture.

The risk of roots affecting the structural integrity of your property should not be a barrier to planting trees or moving to an area where trees are in abundance. Understanding tree behaviours and their relationship with the surrounding environment can help to manage their influence and reduce the likelihood of damage to the home or a commercial premises.

[1] D.F. Cutler, I.B.K Richardson (1989) Tree Roots and Buildings, Longman, London.

How to build homes that stand the test of time

In 2015 the Government set out with the ambition to deliver one million ‘net additions’ to the housing stock by 2020, which included conversions and changes of use. Property developers had two clear options: build more housing or renovate and convert existing buildings.

In January 2021, official estimates suggested that, in order to meet demand in England, 345,000 new homes needed to be built every year. Despite a record year in 2019/20, statistics from the Ministry of Housing, Communities & Local Government revealed that only 243,770 homes were delivered, just over 100,000 short of the requirement.

New Builds

As time is critical for property developers, it’s incredibly important that there are as few setbacks as possible and that they are rectified quickly. With the obvious need for new homes, house builders and developers need to find stable ground to build on, and foundation soil that is protected against environmental factors.

With extreme weather in the UK becoming more common, new buildings must be able to withstand the elements to prevent foundation damage and subsidence. Building as quickly and as cheaply as possible, however, can increase the risk of structural issues and cause longer-term problems.

It’s common for new buildings to settle in their first few years. This shouldn’t be a cause for alarm unless the movement is severe or ongoing as it may be caused by subsidence. In such cases, re-homing homeowners or tenants and opting for traditional concrete underpinning work can be a slow and tedious solution. More modern methods, such as Mainmark’s ‘key-hole surgery’ Teretek® resin injection approach, offer a more cost-effective and less invasive alternative. For builders, developers and property owners this solution could save weeks, often with no need to relocate.

Conversions and renovations

If done correctly, renovation can be a much quicker way to provide new homes compared to new builds. Starting with the foundations and ensuring they are sound is the first step to preserving a building’s longevity and will allow for safe and reliable refurbishments to take place. If this is not addressed first, upgrading expensive interior fixtures like doors and windows can become an issue, should the property subside. This is time-consuming and expensive to fix, and the interiors may need to be re-replaced once again.

When assessing the foundations in an existing structure, understanding the soil type is critical. In the UK the most common soil types are clay, sand and silt, fill and organic:

  • Clays

Reactive clay soil swells when wet and shrinks when dry causing subsidence in drier conditions, or heave in wetter areas.

  • Sand and Silt

Structures on sand and silt soils often experience settlement caused by flowing groundwater, a natural underground watercourse or a leaking sewer or stormwater pipe.

  • Fill

Fill is earthen material placed and compacted in a hole or depression. Structures built on fill are susceptible to the same issues as those on sand and silt, especially when water washes away finer material. Settlement is worse if the fill is poorly compacted.

  • Organic

Organic soils, especially peat, are weak and highly compressible making them prone to settlement, as the weight of any structure above causes compaction. Primary settlement decreases over time but can total 100s of millimetres, resulting in significant structural issues.

If there is an issue with the foundations of a building that needs to be remediated, the modern method of resin injection will provide a less invasive alternative to traditional underpinning methods. This method allows both ground strengthening and re-levelling the structure, increasing the likelihood of it staying as intended and serving its purpose for the future.

The race to provide new homes and meet targets continues. With careful consideration given to the underlying ground of any building new or old, builders and developers can work confidently in the knowledge that their project has a head start.

For more information about the solutions required to repair the sinking foundations of a building, please visit, https://mainmark.co.uk/residential/foundation-subsidence/.


Victor Chirilas

Victor is one of the Directors at Mainmark UK, with over 10 years’ experience in project management and construction management. Having joined Mainmark in 2009, he has managed projects in Australia, the UK and New Zealand including the remediation of the Christchurch Art Gallery which was shaken by the 2010 and 2011 earthquakes that hit New Zealand’s South Island, the old Bank of New Zealand building in Kaiapoi and Ultima Furniture’s warehouse in the UK.

Introducing Mark Mc Donagh, Operations Manager, Mainmark UK

Mark joined Mainmark New Zealand in 2011 and has worked on a wide range of exciting projects, including one of our biggest projects to date at the Christchurch Art Gallery, following the devastating earthquake in 2010 and 2011.

Like many employees, Mark has had the opportunity to work for Mainmark in its operations across the world, joining the Australian division in 2015 before moving to the UK in 2018.  Joining the UK team as a Site Supervisor, Mark has since progressed to Project Supervisor and has recently become our Operations Manager.

What does a typical day at work look like for you?

My core responsibilities centre around health and safety, training and overseeing the project delivery process. Another part of my role is to offer technical support to the teams, so most of my time is spent problem solving to ensure we deliver the best solution possible for our projects. I also attend pre-start meetings, and continually review our processes/policies to ensure standards are met. Client liaison is also a large part of my role.

How would you like to see Mainmark grow as a business in the UK?

Over the last few years we’ve really worked on developing our solutions in the UK by creating our unique mobile units for our Teretek resin injection solution and very recently being able to offer our JOG computer-controlled grouting in a mobile unit as well.  This has been a significant achievement for us and allowed us to deliver an excellent solution for our customers.

Our focus now is on creating new technologies that will allow us to develop further into existing markets and new ones, continuing to push the boundaries and take on the projects others in the industry might shy away from.

We are also really focussed on expanding our operations and the addition of our new depot in the south of England is an example of this. Plan to take this further, opening new depots in other locations so that we are able to improve our operational capacity and expand our bandwidth.

As Operations Manager Mainmark UK, what do you hope to achieve in your role in the next five years?

As Operations Manager, my primary focus is on building a strong team and ensuring all employees have the right tools and skills they need to complete the jobs at hand, while promoting Mainmark’s core values. The culture at Mainmark is a big part of how we retain staff and we should be proud of that.

What’s the most rewarding aspect of your new role?

Seeing people grow from within the business is the best part of my role. Mainmark is a great global business and its values on nurturing the talent we have is recognised and allows us to build teams that can take on any job. One of the biggest benefits to Mainmark as a global business, is working with people from all over the world, it’s great to share experiences and learn from each other and it helps improve the team and create new mindsets. Lastly, seeing great feedback from clients is fantastic and incredibly satisfying as we all take a great amount of pride in our work.   

What do you like to do in your spare time?

I have two young children, so the majority of my time is spent with them at the moment. Outside of that I enjoy a range of activities such as snooker, fishing, golf, and watching sports, both on television and in person. I also enjoy listening to podcasts and music when I can.


By Mark Mc Donagh

Mark is an Operations Manager at Mainmark UK. He has a demonstrated history of working in the civil engineering industry. Skilled in Engineering, Ground Improvement, Site Supervision, Construction and Pressure Grouting. Mark has an excellent understanding of the effects of subsidence and has a broad range of experience working for Mainmark across it’s regions.

Maintaining a Heritage Site

heritage church with JOG equipment

Victor Chirilas, Director of Mainmark Ground Engineering, UK discusses subsidence in heritage buildings and when to seek professional help.

Buildings that have stood for hundreds of years have their own cultural and historical significance, but methods and the materials used in their original construction don’t always stand the test of time and issues of subsidence are one of the most common problems.

What are the issues in remediating heritage buildings?

Historic buildings may require remediation work to maximise life expectancy and preserve their historical significance. Traditionally, these older buildings were constructed with shallow foundations or footings, many just resting on the soil or on layers of loose stones, leaving them vulnerable to subsidence. A building with shallow foundations can move with the ground it sits on, whereas deeper foundations transfer the load further down where the soil typically doesn’t fluctuate as much. Heritage buildings often have issues with water ingress into the foundation soil which can also cause the ground to subside. These factors need to be considered when devising an appropriate remediation plan.

How do you maintain a heritage building?

Many heritage buildings have legal restrictions in place to help preserve the building’s integrity and history, so before undertaking any work, consultation with the relevant authority is recommended. There are however a number of things building owners can do to help prevent structural issues occurring before it’s too late.

An important thing to do is assess the drainage. While it may not be possible to make significant changes, it is essential that proper maintenance is conducted. This includes ensuring drains are free-flowing with no blockages that could cause an overflow, as a consistent flow of water leaking into the soil can saturate the ground and wash away part of the foundations.

Assessing the grounds and gardens around the building is also crucial, as the roots of trees and shrubs can suck moisture from the ground and cause settlement if they are in close proximity to a building. If there is a tree close to the property, make sure it is managed and maintained so that it does not become a problem and when planting new trees ensure that they are not close to a building.

How do you know when an historic building needs specialist work?

Movement in old buildings is normal, but professional help should be sought when this movement is ongoing and begins to threaten the use or safety of the structure.

New cracking is a good indicator here, if there are cracks over 5mm in size that are continuing to grow, then consult with an expert to assess the underlying cause which could be subsidence. They may recommend ground engineers to help strengthen the foundations and stabilise the structure preventing future movement, as well as raise or re-level the building and reduce, or even close the cracks back up.

Can subsidence be repaired under a heritage building?

To an extent all structures can have their foundation ground issues remediated, but with heritage sites the aim is to strengthen the ground and preserve the structure without causing any other damage.

There are typically two options available; traditional concrete underpinning or more modern resin injection methods. At Mainmark, our proprietary Teretek® engineered resin is a two-in-one solution that can improve ground bearing capacity and re-level structures, with minimal intrusion.

The process is likened to key-hole surgery because it is injected through very small tubes into the ground beneath the foundation in a controlled manner, to fill voids and strengthens the ground that has subsided. This can also help raise the building back to level. In cases where more substantial ground strengthening or lift is required, Mainmark’s JOG Computer Controlled Grouting technology is a reliable and accurate solution which can be used in conjunction with Teretek.

As subsidence continues to become one of the biggest problems affecting older buildings in Britain today, it is critical that owners are aware of the advanced solutions now available, helping to effectively repair the ground to ensure the property stands on stable foundations for many more years to come.

For more information about the solutions required to repair the sinking foundations of a heritage building, please contact us on 0800 975 0507 or visit, https://mainmark.co.uk/asset-owners/sectors/public-buildings/


By Victor Chirilas

Victor is one of the Directors at Mainmark UK, with over 10 years’ experience in project management and construction management. Having joined Mainmark in 2009, he has managed projects in Australia, the UK and New Zealand including the remediation of the Christchurch Art Gallery which was shaken by the 2010 and 2011 earthquakes that hit New Zealand’s South Island, the old Bank of New Zealand building in Kaiapoi and Ultima Furniture’s warehouse in the UK.

How can industry move towards a greener way of working?

Safety gear kit close up

Mainmark’s Technical Sales Engineer, David Hedley BEng (Hons), discusses the key issues currently facing the UK building, construction and infrastructure industries.

 The construction industry is known for its heavy use of natural resources, which is often an unavoidable part of the process. However, as the UK Government becomes more conscious of climate change and its impact on the world there is an increasing drive to re-think the way we build and re-design the built environment.

The construction industry has come together to call for the government’s ‘Build Back Better’ slogan to pave the way for investment into smarter carbon conscious building projects and for the opportunity to improve existing buildings and infrastructure. The budget announcement on the 3rd March confirmed this priority with the first ever UK infrastructure bank being set up to finance public and private sector green industrial revolution projects and consumers are being offered the chance to put their savings towards supporting green projects. This is the opportunity for a real turning point, but barriers still remain.

What are the current barriers to greener construction?

One way to reduce the impact of construction projects is to focus on repairing and remediating rather than re-building. But, remediation to existing structures is often seen as a labour intensive task and traditional methods such as demolition and rebuilding are preferred. Becoming more sustainable requires a change in mind-set, to think about the kind of innovation and technologies  available, to operate more efficiently with less negative environmental impact and with an aim to restore, not re-build, where possible.

This mind-set is not limited to the building sector, as we see this issue frequently in UK infrastructure as well. According to the Asphalt Industry Association (AIA), over 40% of the local road networks in the UK require maintenance within the next year and the cost to deliver these repairs continue to outweigh the budget set aside by the government. The result is often a quick patchwork fix which does not eliminate the problem at its root cause and therefore can require attention multiple times. This is not the best way to keep costs down and cut carbon emissions, and as an industry we need to look at addressing these issues at the root cause to create longevity in our built environment, and truly ‘Build Back Better.’

Time and resources

Construction projects often require the use of heavy plant equipment which take time to operate and emit CO2 in the process. While work is underway to look at ways to power plant and equipment differently, such as Hydrogen powered diggers, we still need to take this opportunity to think differently about the way we undertake projects.

Around half of all non-renewable resources we consume are used in construction, yet modern methods of working can be more sustainable. It is essential that we re-use more of our materials in the process, remediate rather than re-build and use fewer raw materials, eliminating the reliance on complex and often international supply chains that have their own unique challenges.

At Mainmark this is something we strongly believe in. Our resin injection solution Teretek® is used in the process of building and infrastructure remediation and is a sustainable and responsible solution that focuses on preservation rather than replacement. It reduces the need for invasive, lengthy traditional ‘underpinning’ works, that create environmental challenges in the methods used.  It does not affect groundwater, soil quality, or local wildlife – making the process environmentally inert.

For more information about Mainmark and its solutions please visit: https://mainmark.co.uk/


By David Hedley

David Hedley is a Technical Sales Engineer at ground engineering specialist Mainmark UK. With a civil engineering degree and over eight years’ experience in the ground engineering sector David is an expert in road infrastructure and efficient highway maintenance, specialising in repairs using geopolymer injection.

Introducing Victor Chirilas, Director, Mainmark UK

Victor Chirilas

At Mainmark, one of our biggest strengths is our incredible team of experienced professionals. We pride ourselves on recognising staff potential and promoting from within where possible. Victor Chirilas, one of the directors of our UK division, is a great example of this.

Victor joined Mainmark as a Technician in Australia 11 years ago, during the great Sydney sandstorm and has been delivering our solutions around the world ever since. having delivered our TeretekÒ geopolymer resin injection solution in Australia for a couple of years, Victor then spent just over four years working in New Zealand, split between the roles of Site Supervisor and Project Supervisor/Manager leading our JOG Computer-Controlled Grouting capability in the field, before heading to the UK in late 2016. When the Mainmark business in the UK began to expand, Victor was among the first on-board as Operations Manager. Last year, he took on the role as a Director at Mainmark UK, along with his colleague Robbie Blanchfield, and is now helping to lead the team toward a bright future.

We recently sat down with Victor to find out more about him, his work, and his vision for the future.

Tell us a bit more about your background and your role at Mainmark?

I have always been a mechanically minded and process-driven person but with my background in technical and media studies, I also have a keen eye for visual imagery. This really suits my role at Mainmark as am comfortable both on and off the tools.

I was born in Romania and grew up in Sweden before moving to Australia in 2009 where I started my journey with Mainmark, as part of the delivery team on site.  I worked on many Teretek resin projects across Australia before moving to join the Mainmark team in New Zealand, gaining more experience on a range of significant projects.

I have enjoyed working on larger residential properties and commercial buildings, and a particular highlight for me was working on the remediation of the Christchurch Art Gallery which was badly shaken by the earthquakes that hit New Zealand’s South Island in 2010 and 2011. As the foundation ground suffered quite severe liquefaction, the 33,000 tonne building lost ground support. The Art Gallery’s footings sank unevenly across the 6,500m2 footprint of the building. Subsidence was as great as 182mm in some places.

We were able to re-support and re-level the structure all while staff continued to occupy the building. You can read about the project in full here.

Can you tell us what a typical day looks like for you in your current role?

I am always focussing on the bigger picture and the ambitious growth plans we have for our UK division. This involves developing the people we have, our processes and procedures, to create an environment where people can thrive and deliver excellent results for our clients.

No two days are the same which makes it interesting, exciting and challenging all at the same time. My day-to-day tasks range from, sales and project support, equipment R&D, HR and marketing support. I juggle this while developing new and existing client relationships and always looking ahead at the bigger picture to meet our targets and focus on business development. From my early morning cup of coffee and brisk afternoon walks, to late catch ups with our overseas colleagues, it all helps to keep the focus that is needed to reach our goals.

What would you like Mainmark to do more of as a business in the UK?

We’re always looking to build on our portfolio in the commercial sector and grow our influence in the wider construction sector as a whole.

In the B2C residential space we know that we have a competitive solution for general subsidence problems that occur, and one of our aims is to become a household name when it comes to subsidence repairs.

Because our techniques can be applied in all sectors and are scalable to meet the demands of almost any project it makes it very exciting to be part of leading this organisation into the future.

How does the UK work differ to the projects you have been involved in Australia and New Zealand?

Oh, the lack of parking! In all seriousness, the work we do in the UK is often located in densely populated areas where space is limited. This means logistically we need to be more agile and re-think how we deliver our services. Mainmark’s solutions already take a very modular approach, but we’ve had to take this a step further. For example, in the UK we had to develop a way to make our solutions even more mobile by delivering our Teretek resin injection solution from smaller bespoke vehicles. 

What do you hope to achieve in the next few years as one of the recently appointed Directors at Mainmark UK?

My main goal as one of the UK Directors is to focus on sustainable growth in markets that are ready for the services we provide. I would like us to continue to develop into different markets where we can share our global expertise, for instance in the infrastructure sector. Aside from furthering our core offerings to a wider audience, we also have several more technologies yet to be deployed. This brings great excitement to what the future will hold for the UK team.

With this said a key goal for the business and for me personally, is to continue investing in our people to develop the talent we have, as well as providing opportunities to grow and to bring more people into the Mainmark family.

What’s the most rewarding aspect of the role?

We’re all really passionate about what we do here, so seeing people around me develop and become effective within their roles and establishing great careers within Mainmark, is definitely the most rewarding aspect for me. Together we can achieve great things.

What do you like to do in your spare time?

I have a range of interests outside of work, I am a keen photographer, I enjoy podcasts with a coffee in hand and naturally with an engineering mindset, I also like building things and working with cars – there’s usually a ‘project’ on the driveway or in the garage!

I also like to travel but due to the ongoing COVID-19 situation that’s been put on hold for the time being. I’m really looking forward to being able to get back out again soon, but until then a cold beer with some rock music on the garage stereo keeps me happy while I work away.


Victor Chirilas

Victor is one of the Directors at Mainmark UK, with over 10 years’ experience in project management and construction management. Having joined Mainmark in 2009, he has managed projects in Australia, the UK and New Zealand including the remediation of the Christchurch Art Gallery which was shaken by the 2010 and 2011 earthquakes that hit New Zealand’s South Island, the old Bank of New Zealand building in Kaiapoi and Ultima Furniture’s warehouse in the UK.

Issues Facing the UK’s Road and Infrastructure Networks

Evening view UK Motorway Services Roadworks Cones

The UK’s road and infrastructure network is in constant need of upkeep and traditional remediation methods are often too slow to keep our networks running in a timely, cost-efficient manner. This ultimately leads to much public frustration and loss of confidence in our Government’s ability to, quite literally, take us where we want to go. Mainmark’s Technical Sales Engineer, David Hedley BEng (Hons), discusses the key issues currently facing UK infrastructure.

Whilst we would all like users to feel comfortable and safe using our country’s infrastructure, from motorways to airports, it is no small job to ensure this is the case. Through collaboration and innovation, there is no reason why we shouldn’t be able to find long-term solutions to the problems at hand; to rebuild and sustain the public’s trust in our infrastructure networks.

Maintaining roads and other infrastructure networks – such as railways, ports, airports and bridges – and ensuring that they are durable enough to stand the test of time is no small task. From increased dynamic loads and harsh weather conditions to ground subsidence and settlement, there are plenty of factors that can affect the structural integrity of the systems we rely on every day.

These causes can all lead to a wide variety of issues that, in-turn, require effort and expertise to overcome. There are five key issues facing our country’s infrastructure, and solving them is vital to keep the UK’s road and infrastructure networks safe, stable and sustainable.

Structural foundation damage

It might seem obvious, but one of the biggest issues facing our road and infrastructure systems is the ongoing deterioration and damage to their foundations. Over 40% of the local road network in the UK is classed as AMBER or RED by the Asphalt Industry Association (AIA), meaning they require maintenance within the next year. At their current state, however, it is estimated that it would take up to 14 years to return all local roads in the UK to a stable condition [1]. This might take the form of fixing cracked pavements, stabilising uneven ground or repairing leaking concrete road slab joints, to name just a few. These often tend to be the symptoms of more complex, underlying causes that require attention and remediation at the root.

Increased maintenance costs

When faced with problems like un-level or unstable ground, those responsible for the maintenance of our road and infrastructure networks in the UK often face worryingly high costs for repair. Recent reports suggest a backlog of repair works worth £11 billion currently exists across the UK [2]. Even so, the Government budget for tackling road repairs over the next five years sits at just £2.5 million. It is an unfortunate truth that most traditional methods of remediating subsidence and settlement tend to be very expensive and thus create an additional hurdle to solving these issues.

Increased accidents

When roads and other infrastructure needs repair, the risk of accidents, and other safety issues occurring, tend to increase exponentially. In a worst-case scenario, ground instability, potholes and even sink holes can lead to serious damage or injury. These are some of the most serious issues caused by foundation ground deterioration and the most in most urgent need of a sustainable solution.

Disruptions to daily operations

A bothersome side-effect of carrying out the works necessary to remediate structural damage that has affected roads and other infrastructure, for example bridges and culverts, is that most traditional methods are both time-consuming and cause mess. More often than not, they lead to disruptions in the day-to-day operations of the network and can be a huge burden on the transportation system, such as when roads need to be re-routed. Inefficient travel and more time spent in traffic not only affects our daily lives but also has an impact on the economy.

Losing public trust

It is sadly common for the general public to lose trust in the widespread road and infrastructure systems they use every day. By using traditional repair and remediation methods for roads, railways ports and bridges, the process is often costly, causing greater delays and disruptions.


By David Hedley

David Hedley is a Technical Sales Engineer at ground engineering specialist Mainmark UK. With a civil engineering degree and over eight years’ experience in the ground engineering sector David is an expert in road infrastructure and efficient highway maintenance, specialising in repairs using geopolymer injection.

Collaborating with trades to remediate properties

Safety gear kit close up

Cracked walls, uneven floors, footpaths, driveways, jammed windows and unaligned doors can all be signs of potential problems with foundation ground. Homeowners who spot these problems around their home often start by calling upon tradespeople to help restore their home to its original condition.

However, as these issues often require a more technical engineered solution, Mainmark is frequently called upon to help. Mainmark’s Teretek® non-invasive resin injection solution is frequently used as a cost-effective way to improve ground-bearing capacity and to re-level buildings that have been impacted by foundation subsidence issues.

Consultation and referral between the homeowner, Mainmark, and speciality trades (such as landscapers, plasterers, plumbers and builders) may take place either before or after ground improvement works have been completed, with different trades each playing an important role in the remediation process.

Following are a few examples of the types of ground issues different trades might encounter when undertaking residential remediation projects.

Landscapers and arborists:

Landscapers can help assess soil conditions at a property while arborists can identify trees with potentially invasive root systems that may be contributing to blocked drains and cracked water pipes. These can all be causes of a home’s foundation ground subsiding. However, trees can also be beneficial for drawing up excess moisture from the ground, so removing trees can sometimes lead to differential soil movement. Homeowners can be guided by a landscaper to help ensure trees are planted at an appropriate distance from the home, driveways, patios and footpaths to ensure this doesn’t become an issue. Landscapers can also provide guidance on suitable retaining walls for different zones around the home and the impact that any new paving may have on site-drainage.

Plumbers:

Leaking sewers and water main pipes can weaken a home’s foundations, which is why it’s critical to catch signs of a leaking pipe or cracked drain as early as possible. If not treated it could lead to homes subsiding at different points, or indeed over their entire property. Damaged or unconnected downpipes and overflowing gutters can also cause complications as soils wash away. This is why engaging a licensed plumber at the first sign of a leak, who knows what to look for, can help avoid longer-term ground problems and significant structural damage.

Builders, plasterers and painters:

Wall cracks are a common first sign of potential foundation movement under a home. Therefore, it’s important that homeowners avoid painting or patching plaster over a crack without investigating the underlying issue first. A professional builder can help homeowners differentiate between minor cracks and possible symptoms of a more serious structural issue. Small hairline cracks are usually the result of seasonal expansion and contraction of soils beneath the building over time. These are generally not a cause for concern and can be patched with a flexible filler and repainted. Problematic wall cracks, however, will typically start at windows, doorways or corners of buildings, and they are usually wider than 5mm (about the thickness of a little finger).

Homeowners can take action to help fix large cracks like these, which have been caused by ground subsidence, by re-levelling the home’s foundations. This can be done using a non-invasive method such as Mainmark’s Teretek® resin injection solution. While this will generally result in wall cracks narrowing or closing up, the area may still need cosmetic finishing with the help of a plasterer or painter. With brickwork, some re-pointing or mortar joints may be required, and with plaster or render walls, some patching and repainting is often needed as well.

Maintaining and restoring homes that have been impacted by foundation issues is often a team effort and the type of trades required to support remediation work will depend on the underlying cause. Mainmark has raised, re-levelled and re-supported homes and other residential buildings across the globe for more than 25 years. Providing fast, cost-effective and non-invasive alternatives to traditional underpinning methods, with our experienced team working collaboratively with other trade professionals to help complete the remediation of many homes.


By Robbie Blanchfield

Robbie is the Commercial Manager at Mainmark UK, with over 10 years’ experience in the construction and civil industries across the world, including UK, Ireland, North America, Australia and New Zealand. Experienced in both risk management and contracting, he has been involved in many civil and infrastructure projects including the remediation of the Christchurch Art Gallery which was shaken by the 2010 and 2011 earthquakes that hit New Zealand’s South Island, the old Bank of New Zealand building in Kaiapoi and Ultima Furniture’s warehouse in the UK.