Greenwich · Greater London
Extension pulling away repairs in Greenwich
The ground under Greenwich and Greater London varies street by street, and extensions built on shallower footings feel those differences first. A trial pit and a drain survey usually tell an engineer how the extension’s foundation is coping.
Guide price from£750per junction inc VAT
- Postcodes
- SE3, SE7, SE9, SE10, SE18
- Population
- about 290,000
- Area
- Greater London
- Pricing region
- London
What is the ground like in Greater London?
Greenwich takes in postcode districts including SE3, SE7, SE9, SE10, SE18, with about 290,000 residents. Neighbouring towns we cover: Lewisham (4 miles), Newham (4 miles) and Bexley (4 miles).
Greater London is one of the parts of the UK where clay soils are most likely to move with the seasons. Ground movement here is more often linked to soils, drains and trees than to mining. Housing stock in Greater London: Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.
What to expect when we carry out extension pulling away repairs
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.
Choose the fix
The engineer decides between ties, a movement joint or underpinning. We confirm a fixed price in writing once the repair is specified, covering the junction, flashings, internal finishes and any foundation work.
Repair the junction
Drains are repaired first if they are leaking. The joint is then tied, formed as a movement joint or rebuilt after underpinning, with roof flashings reset so the junction stays watertight. Building control is handled where needed.
Is it time for extension pulling away repairs? Common signs
- Mastic or render at the joint repeatedly splitting open
- Patio doors or windows in the extension starting to bind
- Floor level dropping where the extension and house floors meet
What should you budget for extension pulling away repairs in Greenwich?
For Greenwich we use London rates. Treat the table as a budget guide, inc VAT; the price you pay is the one on your written quote.
| 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 |
Repair options we may recommend
Junction crack repair with stainless ties
The open joint is cut out, stainless ties or helical bars are fixed across it into both the old and new masonry, and the joint is repointed or rendered to match. Inside, the corner is replastered. This suits extensions that moved once and have since stopped.
Best for: Settled extensions with a stable gap at the junction
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
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.
Your extension pulling away repairs questions
How much should I budget for extension pulling away repairs in Greenwich?
Guide prices for extension pulling away repairs in Greenwich 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.
Can you survey a property in Greenwich?
We do. Greenwich and the surrounding area are covered, including nearby Lewisham and Newham. A free initial assessment from your photos is the first step.
Why do houses in Greater London crack?
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.
Can a drain under my extension cause it to move?
Yes, a cracked or displaced drain beneath or beside an extension can soften clay or wash away fine soil. A CCTV drain survey usually finds it. Repairing the drain is often the first and most important step before any repair to the walls.
Related work in Greenwich
- Concrete repairs
- Subsidence repairs
- Boundary and garden wall repairs
- Floor joist repairs
- Crack stitching
Extension pulling away repairs near Greenwich
Send photos of the extension junction at your Greenwich home, inside and out, and we will give a free initial assessment and a guide price.