Subsidence is the downward movement of a property as a result of damage to the subsoil. The word often instills fear into a homeowners mind as it is one of the most serious problems that a home can endure.
Tree root damage is estimated to be the cause of 70% of all subsidence cases…
Affecting your home’s structural safety, it can also influence the resale value, but don’t worry, we’re not here to panic you. At Dart & Co Foundations we are experts in piling, underpinning and building foundations, so to find out what the causes are and how to fix the issues, read on..
What causes subsidence?
This specific home issue occurs beneath your home when the ground collapses or sinks lower into the building foundations.
There are many contributing factors that make subsidence more likely to occur. Subsidence is usually caused by a combination of circumstances with five significant factors being:
The type of subsoil: clay sub soils are especially prone to shrinking and bulging, hot and dry weather can result in clay shrinkage.
No foundations: Homes and building structures with inadequate foundations will naturally be at higher risk of subsidence damage.
Compromised land: Land that has been mined or contaminated is at further risk of subsidence damage. Properties built over land whose structural integrity has been compromised.
Drain failure: Broken or damaged drains can result in soil being consolidated, therefore increasing land vulnerability.
Moisture content of soil: Clay loses its flexibility when it is open to continuous moisture deficit and is a long-term condition that can result in subsidence damage.
Trees planted to buildings: Trees and large bushes planted in close proximity to a building will draw moisture from the surrounding soil up to twice their mature height. This moisture extraction will shrink the subsoil and could affect the integrity of the structure.
Step 1: Spot the subsidence
It is important that you keep an eye out for any warning signs, if you think you’ve noticed some already, call your local piling contractor and inform them of the issue. Below are some of the most common warning signs that can present a possible subsidence problem.
- Rippling wallpaper
- Doors & windows sticking
- Diagonal cracks that are wider at the top than at the bottom (typically the thickness of a coin)
- Loose bay windows
- Signs that a new extension is moving away from the main building
Remember, these signs may or may not be the result of subsidence, it’s important to keep the following in mind:
If a crack is caused by subsidence, it will be usually be thicker than a 10p coin (more than 3mm), diagonal, and wider at the top than the bottom, visible internally and externally, found close to doors and windows.
Step 2: Diagnose the issue
The quicker subsidence damage is recognised and diagnosed, the faster it can be remedied. Your specialist foundations contractor will be able to recommend the best course of action once subsidence has been confirmed, and at Dart & Co, we are proficient in identifying and fixing foundation issues.
Determining whether the problem is definitely subsidence damage can take some time. Specialist monitoring from your building company may be required over a period of time to ensure that cracks are a result of a larger problem.
Step 3: Fix it
Professional underpinning is usually required for harsh cases of subsidence. Carrying out this type of repair work will usually prevent further movement of the foundations. The process can be lengthy the size of the property and the extent of the damage will affect the solution cost.
Other solutions may be attempted before underpinning, as few as only 10% of properties suffering from subsidence issues will require underpinning. In some cases, trees can be removed as a quick solution to the problem.
Tips on preventing subsidence
- Avoid planting trees or shrubs too close to your home
- If foliage is already in place, don’t dig it up as this can cause water logging
- Ensure that external pipes and plumbing are well maintained to prevent leaks
How Dart & Co can help
As foundation building experts in Exeter, we offer competitive prices and solutions to building foundations and structure issues.
Please contact us today if you require a quote or have concerns about subsidence damage in your home or property.