Understanding Subsidence in Dorset: Causes, Identification, and Solutions

Subsidence is a serious concern for homeowners, especially in areas like Dorset, where the geological composition and environmental factors can contribute to ground movement. In this blog, we’ll explore the causes of subsidence in Dorset, how to identify the warning signs, and what steps to take if you suspect your property is affected.

What Causes Subsidence in Dorset?

Subsidence occurs when the ground beneath a property sinks or shifts, leading to structural damage. Several factors contribute to subsidence in Dorset, including:

1. Soil Composition
   Dorset has areas of clay-rich soil, which expands and contracts with moisture levels. During dry periods, the soil shrinks, leading to movement beneath foundations.
2. Coastal Erosion
   With much of Dorset’s coastline being exposed to erosion, properties near cliffs or shorelines can experience shifting ground over time.
3. Underground Water Extraction
   Excessive groundwater extraction or natural fluctuations in the water table can weaken the soil, making it more prone to subsidence.
4. Tree Roots and Vegetation
   Large trees near properties can extract significant amounts of moisture from the soil, leading to shrinkage and movement beneath foundations.
5. Mining and Quarrying History
   Parts of Dorset have a history of quarrying and mining, which can leave voids underground, increasing the risk of subsidence.
6. Leaking Drains and Pipes
   Persistent leaks from underground pipes can erode the soil, creating instability under a property.

How to Identify Subsidence

Recognising subsidence early is crucial to minimising damage. Common warning signs include:

• Cracks in Walls – Look for diagonal cracks that appear suddenly, especially around doors and windows.
• Doors and Windows Sticking – If previously smooth-operating doors and windows start sticking, the frame may have shifted due to ground movement.
• Uneven Floors – A sinking foundation can cause floors to feel uneven or sloping.
• Separation Between Walls and Extensions – If an extension or conservatory starts to pull away from the main structure, it could be a sign of subsidence.
• Gaps Between Walls and Skirting Boards – Visible gaps inside the home can indicate movement in the foundation.

What to Do If You Suspect Subsidence

If you notice any of the above signs, take the following steps:

1. Monitor the Issue
   Take photographs and measurements of any cracks to track their progress over time.
2. Contact a Structural Engineer
   A professional assessment can confirm whether subsidence is occurring and determine its severity.
3. Notify Your Insurance Provider
   Most home insurance policies cover subsidence, so contact your insurer as soon as possible to begin the claims process.
4. Check for Leaks
   Inspect drainage systems for leaks and repair them promptly to prevent further ground erosion.
5. Manage Nearby Trees
   If tree roots are causing the issue, a tree surgeon may recommend pruning or removal to stabilise the soil.
6. Consider Underpinning
   In severe cases, underpinning—reinforcing the foundation—may be necessary to stabilise the structure.

Final Thoughts

Subsidence can be a worrying issue, but early identification and professional intervention can prevent extensive damage. If you live in Dorset and suspect subsidence, act quickly to minimise risks and protect your property’s value.

Contact us should you wish to discuss any subsidence issues you may have or suspect