Why summer can be challenging for properties 

The summer weather can increase the risk of ground movement and subsidence, causing damage to the property’s foundations. Here’s why: 

Clay shrinkage 

Clay-rich soils are a leading cause of subsidence. This is because when water evaporates during hot, dry spells, clay soils dramatically lose their volume, causing the ground to shrink and crack and struggle to withstand the weight of the structures above it. 

Trees 

Trees, especially species that have a high-water demand such as oaks, willows and poplars, can pose a serious risk of subsidence, particularly in clay soils. Their roots extract large amounts of moisture, causing the soil to dry out. This can lead to property foundations sinking and visible structural damage such as cracking and uneven floors. 

Leaking pipes/damaged drains 

Poor drainage can cause moisture build-up or pooling in the surrounding soil, causing the soil to erode or wash away. This can increase the risk of ground shrinkage and eventually lead to subsidence. 

How can I spot the signs of subsidence early?  

So, how do you tell if your house may be experiencing subsidence? There are some telltale signs to look for: 

• Cracks that are wider than 3mm (roughly the size of a 10p coin)

• Diagonal cracks that typically appear around windows, doors or at the joints between extensions and the main house

• New cracks that grow longer and wider

• Wrinkling wallpaper in corners

• Sloping floors

• Jammed doors and windows

• External cracks in the brickwork or paving

If you spot any of these signs, it’s best to seek professional advice. The earlier the better as it helps prevent further damage. 

How can I reduce the risk of subsidence?  

Although there are numerous factors that can contribute to subsidence issues, there are some steps you can take to reduce the risk.  

Manage trees 

If you want to plant trees on your property, you should ensure that they’re planted at a safe distance from your foundations. Remember, tree roots branch out away from the tree in search of moisture, disturbing the soil and potentially causing ground instability. Trees such as willows and poplars have extensive root systems that can spread 30-40m, increasing the risk of subsidence. Planting smaller trees with less invasive roots such as hazel or rowan can reduce the risk of foundation issues and soil instability. 

Monitor soil moisture

Dried out soil contracts and may develop cracks, which can disturb the stability of the foundations. During long dry periods, consider watering the ground for 15-20 minutes during early morning or early evening, to help keep the ground damp but not over-saturated.

When should I seek professional help with subsidence?  

If you notice any of the signs of subsidence, it’s best to seek professional advice from a surveyor or ground engineer as soon as possible, especially after a long dry spell.  

It’s worth noting that if you spot minor or hairline cracks, this can be a result of natural seasonal changes and is usually nothing to worry about. However, if these cracks rapidly increase or grow wider, then getting a professional opinion is the best course of action. 

The Mainmark solution  

If you suspect subsidence is occurring on your property, ground engineering experts such as Mainmark can conduct a subsidence survey on your property. This involves assessing the ground conditions where needed and completing a soil analysis to determine the severity of the issue and recommend the best remediation works.   

Mainmark can improve ground conditions and strengthen soils using modern, non-invasive techniques including resin injection and computer-controlled grouting. These solutions provide an effective, faster alternative to traditional methods such as mass concrete underpinning or piling.  

Additionally, where trees are contributing to ground movement, Mainmark can install root barriers to manage root growth. Installed below ground, these barriers redirect roots away from structures, with a copper element deterring root penetration. This enables trees to be retained while protecting foundations and supporting more consistent ground conditions.

Summer subsidence may be a cause for concern for many homeowners, but it’s important to remember that not all homes are at risk. Understanding the causes of subsidence and being able to identify the common signs can help you mitigate the risks and take action early if necessary. If you need further advice, speak to Mainmark today.