STEP-BY-STEP SUBSIDENCE GUIDE

Written by

Emma Myrie

Insurance Underwriting Expert

Reviewed by

David Joyson

Home Insurance Expert & Customer Champion

UNDERSTANDING WHAT TO DO AT THE FIRST SIGNS OF POTENTIAL SUBSIDENCE

WHAT is SUBSIDENCE?

Subsidence occurs when a building’s foundations begin sinking due to downward movement in the ground, typically after soil under the building dries in hot weather, or when underground pipes leak and the soil beneath the foundations weakens.    

WHAT CAN YOU DO ABOUT SUBSIDENCE?

Dealing with subsidence affecting your home is, unfortunately, never a quick fix. There is a process that you need to follow, which starts with spotting the first signs and getting a firm diagnosis of subsidence before you can move on to carrying out works to fix the problem and clearing up afterwards. This article explains these steps in more detail.

WHAT ARE THE SIGNS OF SUBSIDENCE?

To recognise subsidence in your home, you need to know what you’re looking for. Some of the tell-tale signs are:

• Cracks – Cracks are the most notorious symptom of subsidence. They will likely appear either internally in plasterwork or externally in brickwork.
• Sticking doors or windows – If features of your home begin sticking for no apparent reason, subsidence may the cause.
• Rippling or peeling wallpaper – The damage caused by subsidence will often manifest in imperfections in your wallpaper. Peer underneath and you’ll likely find cracks.

STEP 1: SPOTTING SUBSIDENCE

The cracks caused by subsidence will often appear around windows or doorframes, so be extra vigilant about any unexplained damage you see in these areas. These cracks will often expand over time, tapering diagonally across the walls, so if you do spot a fracture that appears to be growing, it’s worthwhile getting it checked out. 

STEP 2: TAKING ACTION

Firstly you should contact a surveyor who can review the property and make an assessment as to whether the issues are being caused by subsidence. If the surveyor confirms subsidence you should contact your home insurance provider immediately. The quicker subsidence is diagnosed, the more likely that it can be rectified.

Most insurance companies will send a loss adjuster to your house to assess the potential cost. Your insurer will then be able to recommend the best course of action once subsidence has been confirmed, and will be able to direct you towards any specialist contractors that you might require. Depending on your cover and the magnitude of any damage, you may be required to source your own subsidence repair professionals.

STEP 3: WHAT YOU NEED TO KNOW ABOUT DIAGNOSING SUBSIDENCE

Determining whether your problem is actually subsidence can take some time. Monitoring may be required over a period of several months to ensure that cracks are indications of anything more than superficial. If the movement of the house is ongoing and damage continues to worsen then your insurer may decide to monitor your property over several months before agreeing repairs. However, if the issues are not caused by subsidence it can be the case that an expert can rule it out immediately.

STEP 4: FIXING A PROBLEM

Underpinning might be required for more severe cases of subsidence. Carrying out this type of repair work will usually prevent further movement of the foundations. The process can be lengthy and expensive, costing anywhere between £5,000 and £50,000 depending on the size of the property and the extent of the damage. Though figures differ, it is estimated that as few as only 10% of properties suffering from subsidence will require underpinning. The Institute of Structural Engineers advises that you should attempt every other possible solution before resorting to underpinning.

Tree root damage is estimated to be the cause of 70% of all subsidence cases (according to Which? consumer magazine), as tree roots draw moisture from the soil beneath your home. This problem can become more pronounced during extended dry periods, particularly in regions where the soil base is comprised mainly of clay.

Sometimes trees may be removed to solve the problem. Once the tree has been removed there will be a period of monitoring to ensure that removing the tree has stabilised the ground. It’s important to note that in rare cases removing a tree can lead to the opposite of subsidence, known as ‘heave’. Heave is where the ground beneath a property swells up with excessive moisture caused by the absence of a tree that used to keep the moisture levels low. An arboriculturist (tree specialist) will be able to provide advice on matters involving tree and root control.

Pipework beneath or within your foundations can sometimes cause subsidence, if they leak or burst and cause earth to be washed away. A CCTV drain survey can determine if this might be the problem and, if it is, then remedial work to the drainage system can be carried out. This might eliminate the need for costly and intrusive underpinning procedures.

STEP 5: AFTER SUBSIDENCE

If you have had subsidence problems in the past, it is probable that you will have difficulty finding an insurer to provide you with the home insurance you need to fix it if it happens again.

Though reoccurrence after underpinning might be rare so far, the statistical evidence to demonstrate whether or not a property is more or less likely to begin subsiding again is insufficient and most insurance companies are reluctant to take a chance.