Subsidence – what is it?

Identifying building subsidence

The one major sign of building subsidence is the appearance of cracks in walls or floors dropping. The cracks caused by subsidence are normally of a diagonal nature and will suddenly appear in plaster work inside the building and on brickwork outside. Subsidence cracks will usually be thicker than fine hairline cracks, which may be caused by natural movement of a structure, and tend to be wider at the top.

subsidence crack

Crack caused by subsidence

Floors dropping due to subsidence are also quite clear to spot, look at the skirting around your floors where gaps will appear – or cracks and uneven surfaces. These are problems we can cure without the complete incovenience of excavation.

You can also look for possible signs of subsidence around weak points in the building, such as doors and windows. You may find that doors and windows may stick due to the movement of the building. Building subsidence cracks are also common where an extension meets the main building, indicating that the extension is pulling away from the main structure. We can inject our geo-polymer material beneath an extension to stabilise it and prevent further movement and also in some cases lift it back into place.

Identifying subsidence

Of course, the first step in resolving subsidence issues is identifying its presence. The primary indication that a building is affected by subsidence is the sudden appearance of cracks in the building and walls. These cracks usually present themselves as diagonal in nature and crop up on interior plasterwork as well as the outside brickwork. Natural movements of structures can sometimes result in fine hairline cracks in walls. Subsidence cracks tend to be thicker than these hairline cracks.

Building extensions can help detect whether subsidence is a problem. Subsidence cracks are common at points where extensions meet buildings. These cracks give a clue that they are moving away from each other and remediation may be required.

Doors and windows can also give an indication of subsidence. If affected by subsidence, doors and windows can stick or fail to open and close properly due to the building moving from its original foundations.

Subsidence treatment

The principle of our solution involves injecting one of our expanding geo-polymer materials under your property, the material is pumped into the soils as a liquid and expands under the ground. As the geo-polymer expands it fills the voids in the soils, forces out any water and compacts the soil – this results in a solid stable base under your property’s foundations or floor.

As the material expands in the ground it will follow the path of least resistance until it can not migrate any further; at this point the expansive force of the material begins to push up onto the foundations of your property. We can see when this happens using our laser monitors, which will pick up 0.25mm of movement above the injection point. If we are stabilising the ground we will stop the process at this injection point and move on to the next – we will inject at points at around 1.5m apart to ensure the material is equally spread under the problem area of your property. If we are lifting your floor, we continue injecting material at the injection point until the floor is lifted to the required level.

The material we use does not degrade, it is a permanent solution comparable to concrete, but the process of introducing our geo-polymer to the affected area is faster and cleaner. As a comparison, cement grouting requires heavy machinery and your property becomes a full worksite, as with screwpillars, or underpinning, which requires the excavation of foundation soil. With Geobear we simply drill small holes and inject our material.

Using geo-polymer as a solution to subsidence is the most conveinient method and in most cases the preffered option; other methods, such as underpinning delivered by traditional building contractors, are becoming dated as modern technology evolves.

Please contact us for further information or a site visit.

The cost of subsidence

Ground subsidence is a potentially catastrophic problem for your home or business. If you want more information on the cost of subsidence, then please keep on reading.

Aesthetic impact

There’s an enormous number of problems for your building that result from ground subsidence, ranging from the aesthetic, to the structurally devastating and bank account hammering.

Huge and horrible cracks creeping across your walls, plaster flaking off, wallpaper rucking at the edges and brickwork shifting out of place are all ways that subsidence can make your home or business look worn out and uninviting. This not only makes the building look dramatically worse, this naturally can lead to the fall in value of your home, which could be devastating for you if you’re trying to sell it.

Also, if you’re running a business, nothing makes you look more unprofessional than cracks in the walls and plaster falling off, potentially turning away customers and clients, and leading to unnecessary loss of revenue.

Catastrophic consequences of subsidence

Outside of the threat to the look of your property, there is a multitude of inconveniences, problems and disasters awaiting you if you don’t get your subsidence treated.

Doors and windows, which are structural weak points, might start getting stiff or stuck, due to distortion. Pipework and electrical wiring are also under threat from the sinking and movement of walls. In your home this can be annoying and unpleasant and in a business this can make parts of the building potentially unusable, leading to a waste of money. If you notice issues with your plumbing or lights, then this could be a symptom of ground subsidence.

At the extreme end of potential problems is massive structural damage to your property. If you start to notice significant structural damage, then health and safety becomes your concern, which can be calamitous for a home or a business. For a home, the safety of you and your family are at risk, and for a business, the safety of employees, of customers, clients and of the general public are at risk.

Business property owners have the added threat of legal action potentially being taken against them if these risks ever become a reality. If parts of your building collapse then you can find yourself unable to use it, which leads to huge problems and costs for homeowners and business owners.

Financial implications of subsidence

On top of all that, there’s also the extensive repair costs which you’ll have to weather if you let it get this bad. Structural damage to a building, its wiring and pipework can all potentially be enormous financial costs. Importantly, these extensive repairs dwarf the cost of getting Geobear to come in to sort your ground subsidence.

Untreated subsidence can lead to significant loss of property and structural value as well as costs to your business from inability to use your premises or structures for their planned purpose.

We’ll use our resin injection method to sort out the stability of your foundation, so why take the risk with your property? Do not leave it too late, it’s not worth it.

Please call us to discuss your property, it may be that an indicative price can be provided or we can arrange a free site inspection to understand the extent of your issues.