How to identify subsidence and how to deal with it.
Finding subsidence can cause a lot of headaches for homeowners and cause loss of income for landlords or businesses because of the issues it can cause. In this blog, we will tell you how to identify if your building has subsidence.
Firstly, it is important to understand what subsidence is.
Subsidence means the foundations of the property are moving downwards. It is common for one part of the building to move and another part of the building to remain stable. This differential foundation movement causes cracks and distortion in the walls and floors.
If subsidence is left untreated it could impact the stability of the property. Over time it could also reduce the value of the property or make it hard to sell.
What causes subsidence?
The cause of subsidence will depend on where you live and what geology surrounds your property. A surveyor will conduct research and report on the likely causes of subsidence. Here are a few things to look out for.
- Shrinkage of clay soil
- Drainage leaks
- Houses being built in mining areas, former quarries, or infill sites
How to tell if a crack is caused by subsidence?
It is important to note that not all cracks are caused by subsidence. Some are caused by normal expansion and contraction of the building as the temperature changes from day to night.
- Is the cracking tapered? Is it narrow at the bottom and widening at the top?
- Is the crack mirrored? Can you see it inside and outside of the building at the same location?
- Do you have diagonal cracks? Are they passing through the door and window openings?
- Are the doors and windows suddenly sticking? Has the opening become distorted?
If so, then you should get a surveyor in to determine if it’s subsidence. Delays in getting these types of cracks looked at can cause greater problems further down the line.
To give you an example of cracks caused by subsidence, here are some photos from our client’s property that had severe subsidence after the long dry summer in 2022.
How we identified what caused the cracks in the wall.
We completed a specific defect survey that focused on the cracking in the walls inside and outside the house. After completing our survey, it was determined that an oak tree was causing root induced clay shrinkage subsidence.
In most cases, subsidence such as this is covered by a building’s insurance policy. So often the first port of call would be to contact the building’s insurers who might recommend that an independent surveyor’s report is obtained.
Our advice was to first tackle the cause of the subsidence by employing an arborist (a tree specialist – recommended by us) to advise on tree management/removal. Following a suitable period of time to allow for rehydration of the soil, we advised the repair works to be carried out including a brick stitch repair and finally, for re-plastering and redecoration of the internal area. We were able to offer a pragmatic repair solution without the need for expensive and disruptive underpinning. Cracks in the
What are the other signs?
Cracks in the wall are usually the first thing people notice however there are other signs including:
- Doors and window frames distorting and becoming inoperable
- Cracks at the abutment between the main house and extension/conservatory
- Cracks, distortions or sloping floors.
Can subsidence be prevented?
Sometimes subsidence is unavoidable. Other times we can provide a subsidence risk assessment to advise what can be done to help prevent subsidence.
We get frequent requests for this type of advice when someone is buying a new home.
The conveyancing searches undertaken by solicitors occasionally indicate that there may be issues with ‘ground stability’.
A site survey can identify those subtle signs of historic movement and identify risk factors such as vegetation or leaking drains that might cause future subsidence. Information on the local geology of the subsoils will advise on what preventative works are required.
Can it be fixed?
We have helped to repair thousands of subsidence-damaged properties. On most occasions, the fix is relatively simple. Sometimes ground injection, piling or underpinning may be needed.
On other occasions, there might be other complications such as tight deadlines for the arrival of student tenants, or financial constraints such as keeping a business up and running profitably.
We are independent and pragmatic about what is right for the specific issue. At AIM surveying subsidence is our specialty, so get in touch if you have any queries and have a chat with one of our friendly and knowledgeable surveyors!