Freya Chapman is the Residential Lead at ground engineering specialist, Mainmark UK. She collaborates with arborists, insurers and civil engineers in her role as a Subsidence Forum Committee member to educate homeowners on the sustainable treatment of trees causing subsidence.

Subsidence – where the ground beneath a building or structure starts to sink – is becoming increasingly more common in the UK and Ireland due to changing climate patterns, like droughts and heavy rainfall. For homeowners, subsidence is becoming more of an inevitability, particularly if your property is near water-thirsty tree species, like oak and willow.

Freya said: “Woodland Trust (the UK's largest woodland conservation charity) has said that many of our native tree species are having a mast year, which is a strategy whereby trees produce an increased amount of fruit, seeds and nuts to ensure the survival of the next generation.

“This is a really clever demonstration of evolution and usually occurs every 5-10 years. However, experts are suggesting that with the arrival of another mast year just 3 years after our last one, our trees are in distress following the warmest British summer on record. But what does this actually mean for us?”

Producing fruit is a resource-intensive exercise for trees, which, during hotter periods, must dig their roots a little deeper into the soil to collect enough water. This can cause clay soil to dry and shrink, leading to movement and instability for the foundations of our homes – and costly, time-consuming repairs!

According to Freya, the mast year for the trees could indicate an increased risk of subsidence for our homes and critical infrastructure: “As a global subsidence specialist, we are now looking at how we can sustainably treat tree roots to reduce this costly burden for homeowners. However, we’d like to prioritise the natural environment too.

“For Mainmark, we can achieve this by taking a ‘combined methodology’ approach, prioritising both the homeowner and the natural environment in our problem-solving. Our patented Teretek® resin injection solution is a greener, cost-effective and quick alternative to subsidence repair, which strengthens foundations and relevels the ground without the need for underpinning.

“Furthermore, we work collaboratively with organisations like the Subsidence Forum Committee, to campaign for the development of textile-based root barriers using copper – the only compound that tree roots naturally divert away from.

“Traditional root barriers use cement-based treatments, which are costly, time-consuming and bad for the environment. uPVC barriers can also be used, but they often prevent water from moving freely in the soil, further damaging vegetation. There is more than 17 years’ worth of data to suggest that copper root barriers could provide a solution. It’s also a lot greener and less invasive than traditional methods using cement.

“For homeowners, mitigating subsidence claims while protecting the surrounding vegetation involves simple consultation with ground engineering experts, who can adopt a problem-solving approach using state-of-the-art technologies to protect our trees.”

Mainmark UK is part of the global Mainmark group of companies – founded originally in Australia in 1989, but successfully delivering projects in New Zealand, Japan, Thailand, the UK and Ireland. Through its solutions for releveling, ground improvement and void filling, it has successfully delivered 82,000 projects globally to help futureproof infrastructure from climate-related disasters.