What You Need To Know About Subsidence
For homeowners, the term “subsidence” might sound daunting, conjuring images of lopsided houses and massive repair bills. However, understanding what subsidence is, its causes, early warning signs, and the solutions available can shed some more light on this issue and provide homeowners with peace of mind.
Read on to learn everything you need to know about subsidence and underpinning.
What is Subsidence?
In simple terms, subsidence happens when the ground beneath a building begins to sink. In more extreme cases, it could even cause the structure itself to collapse. This movement can disrupt the foundations of your home, causing it to become misaligned and strained by the instability beneath. While this might sound alarming, the good news is that subsidence can often be rectified relatively easily.
What Causes Subsidence?
As mentioned, subsidence occurs when the ground beneath a building becomes unstable, leading to downward movement of the property. There are various environmental and property-specific factors that can contribute to this issue, and understanding these causes is key to prevention and effective remediation.
Environmental Factors
Subsoil Shrinkage: Clay soils are particularly prone to shrinking during prolonged dry spells. As the soil loses moisture, it contracts, reducing support for the building’s foundation.
Nearby Trees and Vegetation: Large trees and plants with extensive root systems can absorb vast amounts of water from the soil, especially during droughts. This depletes moisture levels in the ground, causing the ground to dry out, settle unevenly and sink.
Leaking Pipes or Drains: Faulty underground plumbing can lead to soil erosion as water escapes washing away the soil, creating voids beneath the property and undermining its stability.
Soil Erosion: Similar to leaking pipes and drain, a natural process such as water run-off, can gradually wash away soil from beneath a property, particularly in areas with poor drainage or on sloping ground.
Historic Mining Activity: Areas with a legacy of mining may have voids or tunnels beneath the surface. Over time, these can collapse or shift, resulting in subsidence.
Property-Related Factors
Older Properties: Homes built with shallow foundations or using outdated construction techniques are more likely to experience subsidence, especially if they were built before modern building regulations came into force.
Inadequate Ground Preparation: Poor groundwork during construction, such as insufficient soil compaction, can lead to instability as the building settles over time.
Variable Weather Conditions: Properties in regions with fluctuating weather changes such as alternating periods of heavy rain and drought are more vulnerable due to the expansion and contraction of certain soil types.
Soil Type and Local Ground History: Properties built on clay, sand, or other problematic soils, or in areas known for historic ground movement, are naturally at greater risk of subsidence.
What are the Signs of Subsidence?
Detecting subsidence early can save homeowners from extensive repairs. Key signs include:
Cracks in Walls: These often form in a zig-zag pattern in both external and internal brickwork, as well as cracks around doors and windows
Jammed Doors and Windows: The windows and doors in your house can become difficult to close and difficult to open if subsidence is at play, because the frames can become warped in the process
Rippling Wallpaper: If there isn’t any damp present, but your wallpaper is rippling, it can signal movement beneath the surface
Extensions Coming Away: If you have an extension or a conservatory that is moving away from the main structure of the house, then subsidence could be the issue you’re experiencing
How to Fix Subsidence
Fixing subsidence requires identifying its root cause and implementing tailored solutions.
The first step is to conduct a thorough assessment by a structural engineer or a surveyor to determine the extent of the damage and the underlying problem, whether it be soil shrinkage, tree root intrusion, or drainage issues.
Addressing the cause is crucial; this might involve improving drainage, removing problematic vegetation, or stabilising soil with moisture-retaining additives. For severe cases, underpinning is often used to strengthen and stabilise the foundation by extending its depth or breadth.
Modern methods such as utilising resin injection technology, can also be employed to fill voids and lift sinking foundations. Once the foundation is secure, repairs to cracks and structural damage can restore the property, ensuring long-term stability and safety.
By using resin injection technology, homeowners can effectively address subsidence issues, ensuring their properties’ stability and safety. While subsidence can initially sound intimidating, understanding its causes and recognising its signs are crucial first steps.
What To Do If You Suspect Subsidence
If you suspect subsidence, consult with experts to assess and address the issue promptly – even if you start with a consultation to confirm or deny issues of subsidence with a subsidence survey.
With the right approach, homeowners can protect their homes and avoid costly repairs in the long run.
So, if you have any concerns or suspect subsidence in your property, don’t hesitate to seek professional help and find a suitable solution to keep your home safe and stable for years to come.
