1. What is subsidence damage?
Subsidence damage occurs when movement in the ground causes movement of the building foundations.
The damage often shows up as cracks in walls or ceilings, often around door or window openings and wider at the top than the bottom. Doors and windows may also stick.
2. What causes it to occur?
Subsidence most commonly occurs when clay soil under the foundations dries up and shrinks, frequently due to moisture extraction by the roots of nearby trees. This type of subsidence typically occurs in the summer following hot, dry weather. The second most common cause is leakage from underground pipes washing away or softening the soil beneath the foundations.
Another less common form of ground movement is heave. This occurs when the ground swells – often when moisture levels increase in a clay soil after removal of trees.
3. Can it be cured?
In many cases subsidence damage can be repaired relatively easily and effectively and without foundation work. This is usually after the cause has been addressed which will typically involve some tree work or repair of a leaking service pipe. In a small proportion of cases, normally where the cause cannot be removed, it is necessary to undertake foundation works.
4. What do I do if I think I have subsidence?
Notify your buildings insurer who will generally be able to help with identifying the cause of the damage and the best course of action to be taken.
5. Is subsidence damage covered by my insurance policy?
Subsidence insurance cover is standard on most domestic buildings insurance policies. If your insurer thinks it may be subsidence they will normally arrange for an expert to inspect the damage and advise whether it is covered by the policy. If arranged by your insurer you will not have to pay for this inspection. Most valid subsidence claims are subject to a policy excess, typically £1000.
6. When will I need to pay the policy excess?
The policy excess is required to be paid when the repairs are undertaken.
7. How long does a subsidence claim take to resolve?
Every claim is different so it isn't possible to give an exact answer. The length of time the claim will take to settle will depend upon how complex the cause of the damage is and what investigations need to be carried out. If it is necessary to monitor the damage, to see if movement has stopped, this is often undertaken over a year period and repairs will not be able to start until this has been completed.
8. Can I sell my house before the repairs are carried out?
Yes, from your insurer's perspective, there is no reason why you cannot sell the property during the course of the claim. It will be necessary for you to tell them of your intention to sell and for you to transfer the benefit of your claim to the new owner. You will also need to agree who will be responsible for the £1000 policy excess.
9. How will my claim be dealt with?
The key stages in a typical subsidence claim are: Investigate cause – following initial assessment, site investigations or a drain survey may be carried out to establish the cause of the movement to the property.
Mitigation – remove the cause of the damage, for example:
- If the damage has been caused by shrinkage of the clay soil supporting the foundations of the building, tree works may be required to reduce the effect on the moisture content of the soil.
- If the damage has been caused following weakening of the soil supporting the foundations of the building by leakage from drains, drains will need to be repaired. Undertake monitoring - following removal of the cause of the damage it is sometimes necessary to undertake monitoring to confirm that this has been successful. Undertake repairs – a schedule of repairs will be prepared which will detail what work will be carried out.
10. What are Site Investigations?
Site investigations are investigations carried out to establish the type and condition of the foundations and soil beneath the foundations. The investigations are carried out to determine the cause of the damage to the property. These can consist of:
- Trial pits - a small pit dug into the ground.
- Boreholes - a deeper hole drilled into the ground to obtain soil / root samples for study.
11. What is a drainage survey?
If the damage could be caused by leaking drains, a survey of the drainage system near the damage may be required. A camera survey of the drainage pipe may be carried out to establish the condition of the drainage system and whether this is contributing towards the subsidence damage.
12. What is crack monitoring?
Crack monitoring is used to establish whether there is any continuing movement of the building. This is generally carried out by installing small metal studs either side of cracks and readings are taken to establish whether the cracks are opening or closing. Monitoring is normally undertaken for between three months and a year, depending on the cause of damage.
13. What is level monitoring?
Level monitoring is sometimes carried out to establish whether there is any continuing movement of the building as a whole and to identify the extent and nature of the movement. Levels are taken periodically on a series of points around the building. Like crack monitoring this is typically undertaken for between three months and a year.
14. What is an Arboricultural report?
If trees and shrubs are considered likely to be contributing towards the movement a specialist may be instructed to inspect the damage and the surrounding trees and shrubs. They report on what can be done to reduce the effects of the trees and shrubs on the structure
SUBS FORUM NEWS
DATES FOR YOU DIARIES 2017- For dates of all of the upcoming meetings and events in 2017 please click here
DISSERTATION INITIATIVE 2017 - The dissertation scheme is to offer a cash prize of £500 for the best undergraduate, final year dissertation for 2017. see the Latest News page.
TRAINING DAY 2016 - This was held on 20 October, BRE Watford - the presentations from this day can be found by clicking here
SUBSIDENCE HANDBOOK – A Practical Guide to subsidence in domestic property - 4th Edition available at a cost of £12.95 (inc p&p)
The Subsidence Forum provides a unique focal point for anyone involved in the subsidence industry delivering a range of benefits.