We might be going through a really cold spell in most parts of the UK, but we should be reminded of last summer with some of the driest and hottest months on record.
A particularly prevalent region, which is well-known for subsidence-prone clay soil, was the South East. The Association of British Insurers (ABI) has reported report that the number of subsidence related claims jumped from 2,500 in Q2 to 10,000 in Q3 – with subsequent pay-outs rising in value from £14 million to £64 million.
Subsidence is the downward movement of ground beneath a property which leads to abnormal stress on the structure and foundations, which can result in cracking and property damage, and typically arises following the removal of underground water. Property is at an increased risk following extended hot weather and dry spells.
The first sign of subsidence is the appearance of cracks in a properties brick or plasterwork. In general, subsidence cracks develop abruptly and exhibit different characterises to other cracks.
There are simple steps property owners can take to avoid potential subsidence. To determine whether your property is subsiding, the ABI’s advice is that subsidence cracks are typically:
- diagonal, and wider at the top than at the bottom
- thicker than a 10 pence coin
- found around doors and windows
Subsidence may also cause doors and windows to stick as the building’s structure becomes distorted.
It is important to note that cracking can occur in a property for reasons unrelated to subsidence. These include the natural settlement of soil under new homes or extensions, thermal and humidity expansions or the drying and shrinkage of building materials (including freshly plastered walls).
Ways to avoid subsidence
- Plant new trees and shrubs at a ‘safe distance’ from your property – review safe distance and tree hazard guidance
- For trees older than the property and within a safe distance, conduct regular pruning to control amount of water used in foliage growth
- Do not remove tress older than the property and within a safe distance, this may cause heave or uplift
- Drains and pipes should be checked regularly to ensure there are no blockages or leaks
- Conduct regular general maintenance including fixing leaking drains, clearing debris from gutters and pruning trees and shrubs
Costs associated with subsidence can be categorised into prevention, investigation, mitigation and repair. Over the last decade, there has been vast improvements in the management and effectiveness of each category. This has largely been enabled by technology advancements and engineering innovations.
Prevention – tracking soil conditions, level monitoring readings and long-term weather forecasts that provide a suite of predictive analytics
Investigation – identifying the cause of the problem, analysing soil conditions, establishing depth of foundations, reviewing historical and geological maps
Mitigation – live remote crack monitoring, video streaming, geo-mapping and data analytics
Repair – modern techniques including screw piling, injection grouting and rehydrating
This is in addition to more traditional repairs such as targeted lifting (jacking) and tree removal. Of course, there is no substitute for skilled adjuster surveyors with a detailed knowledge of subsidence claims. This is particularly important in the interpretation of data pertaining to soil plasticity etc.
Quickly identifying the cause of the subsidence movement is critical as each movement is unique.
Talk to our private client division on 020 8681 4994 to arrange specialist insurance cover.