Dealing With Subsidence
Dealing with subsidence can be a difficult business and it is almost always advisable to seek professional assistance. Subsidence is essentially the downward movement of the ground beneath a building’s foundations, often causing structural damage to the property in question. Acting swiftly is the best way to approach a case of subsidence, though in most cases the problem will not be resolved with great haste. Spotting that you have a subsidence issue is the first step, so it is important that you know what you are looking for.
Cracking on the inside and outside of your walls can be a result of atmospheric conditions and may occur due to the natural movement of a structure over time, but you should always consult an expert if you suspect subsidence. Subsidence related cracks are characteristically tapered and spread diagonally across walls; they are often visible internally and externally and will not close up on their own over time. They will typically begin from around door and window frames, opening wider than 3mm (at which point you should contact your subsidence insurance provider immediately). Doors and windows sticking for no discernable reason are also signs of subsidence, as is rippling wallpaper.
Though underpinning has historically been the go-to option for any diagnosed subsidence case, these days it is used only as an absolute last resort in all but the most severe instances. Most house subsidence insurance providers will begin by implementing monitoring measures. Investigation procedures will differ depending on the nature of your subsidence and the likely cause (which may relate to geographical factors). Consultation with a surveyor might be required as well as various other professionals, such as drain surveyors or arboriculturists. A CCTV drain survey might be needed to check that ground movement isn’t being caused by damaged drains, or to check that drain damage hasn’t been caused by subsidence.
In areas where the soils are composed primarily of clay, such as the South and East of England, the shrinkage of clays is likely to be the cause of a subsidence issue. If there are trees in close proximity to the property, then it is quite likely that they could be exacerbating any subsidence your home might be undergoing. An arboriculturist will be able to advise you on any tree management that may be required. It is vital that you consult someone with specialist knowledge before simply removing a tree, as in certain circumstances this can lead to problems that may be equally (or more) severe than those you already have.
In cases where underpinning is absolutely necessary, you should prepare yourself for a costly, time consuming and possibly traumatic experience. Most standard policies will include cover against ground movement, but if you have previously claimed on your house subsidence insurance then cover may be excluded. Generally, where house subsidence insurance claims are involved, you will usually have to pay around £1000 excess. Underpinning can cost anywhere between £5000 and £50,000, so it is best to explore all other options before undertaking it. Once a subsidence problem has been fixed and the building stabilised, only then should you begin carrying out more minor cosmetic repairs (such as refilling cracks, redecorating walls and rebuilding brickwork as needed) to avoid having to redo work time and again until your home stops subsiding.