Kingston upon Thames · Greater London
Extension pulling away repairs in Kingston upon Thames
If the corner joint in your Kingston upon Thames extension keeps splitting after you fill it, something is still moving. Measuring the gap over a few months, with dated photos, gives an engineer the evidence to recommend the right repair.
Guide price from£750per junction inc VAT

- Postcodes
- KT1, KT2, KT3, KT4, KT5
- Population
- about 170,000
- Area
- Greater London
- Pricing region
- London
How do local ground conditions affect extension pulling away repairs in Kingston upon Thames?
We cover the whole of Kingston upon Thames, including postcode districts KT1, KT2, KT3, KT4, KT5; about 170,000 people live in the borough. Neighbouring towns we cover: East Molesey (3 miles), Ewell (3 miles) and Esher (4 miles).
Much of Greater London sits on clay that shrinks in dry summers and swells in wet winters. Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Greater London: Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.
Extension pulling away repairs prices in Kingston upon Thames
The ranges below reflect typical London costs for extension pulling away repairs, including VAT. Scaffold, access and making good can push a job to the top of the range.
| Item | Guide price | Per |
|---|---|---|
| Junction crack repair with stainless tiesest. | £750 – £2,500 | per junction |
| Movement joint and making goodest. | £500 – £1,500 | per junction |
| Underpinning the extension where needed | £1,250 – £3,100 | per metre of wall |
How we usually approach extension pulling away repairs
Movement joint and making good
Where some seasonal movement is expected to continue, the junction is formed into a proper flexible movement joint with a compressible filler and sealant, so the two parts can move without cracking. Flashings and internal finishes are detailed to suit.
Best for: Minor ongoing movement that does not threaten the structure
Underpinning the extension
If the extension is still dropping because its footings are too shallow or on poor ground, they are taken deeper by mass concrete, beam-and-base or mini-piles. The engineer designs the scheme, and the junction is repaired once the new foundation is in.
Best for: Active movement from shallow footings, roots or soft ground
What happens during extension pulling away repairs, step by step?
Show us the junction
Send photos of the crack outside, the internal corner and any flashing above, with a measure for scale. We give a free initial assessment and an initial view on whether the gap is likely old or still opening.
Find what is moving
An independent chartered structural engineer can inspect, and we can arrange one. A drain survey under the extension, a trial pit at its footing and tell-tale monitoring across the joint are common checks before choosing the repair.
Finish and hand over
Internal corners are replastered, skirtings and coving refixed, and doors or windows in the extension eased where the movement affected them. Records of the repair and any approvals are passed to you.
What to look for before calling about extension pulling away repairs
- A vertical crack or gap where the extension meets the house
- Patio doors or windows in the extension starting to bind
- Daylight or draughts showing through the internal corner joint
Rules for extension pulling away repairs in England
In England, underpinning and other work that alters or strengthens a wall or foundation is building work under the Building Regulations (Part A, structure), so building control approves and inspects it. Like-for-like repairs often are not, and we tell you which applies before a price is agreed. Work to a party wall, or excavation close to a neighbour’s foundations, can also need a notice under the Party Wall etc. Act 1996.
Questions about extension pulling away repairs in Kingston upon Thames
How much will extension pulling away repairs cost in Kingston upon Thames?
Guide prices for extension pulling away repairs in Kingston upon Thames start from about £750 per junction, including VAT, on London rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Kingston upon Thames?
We do. Kingston upon Thames and the surrounding area are covered, including nearby East Molesey and Ewell. A free initial assessment from your photos is the first step.
Is the ground in Greater London prone to subsidence?
Most of Greater London sits on London Clay, among the most shrinkage-prone ground in the UK, with river gravels along the Thames. Subsidence claims here are among the most frequent in the country, especially after dry summers and near street and garden trees. Only an investigation can say why a particular building has moved.
Who is responsible if a recent extension is moving?
If the extension is recent, the original builder, the designer or building control records may be relevant, and you may have rights against the builder. Gather the plans, completion certificate and contract. Insurance often excludes defects in new construction, so check your policy.
Will my extension need underpinning?
Often not. Many separating extensions are fixed by repairing a drain, tying the junction or forming a movement joint. Underpinning is for extensions that keep dropping because their footings are too shallow or the ground beneath is poor, as shown by monitoring.
Other structural repairs in Kingston upon Thames
- Structural surveys and crack monitoring
- Subsidence insurance claim repairs
- Floor joist repairs
- Bay window subsidence repairs
- Structural crack repairs
Extension pulling away repairs near Kingston upon Thames
Photos of the crack, the internal corner and the roof flashing are a good start; send them about your Kingston upon Thames home and we will reply with a view.