Brent · Greater London
Extension pulling away repairs in Brent
An extension pulling away from a Brent house is often a drain problem, a shallow footing or a missing tie-in, rather than a failing building. Finding out which applies decides whether the fix is a junction repair or new foundations.
Guide price from£750per junction inc VAT

- Postcodes
- HA0, HA9, NW9, NW10
- Population
- about 340,000
- Area
- Greater London
- Pricing region
- London
What is the ground like in Greater London?
Brent takes in postcode districts including HA0, HA9, NW9, NW10, with about 340,000 residents. If you are just outside Brent, we also cover Harrow (3 miles), Ealing (3 miles) and Hammersmith and Fulham (5 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. 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 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.
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.
What to look for before calling about extension pulling away repairs
- Extension roof flashing lifting off the original wall
- Daylight or draughts showing through the internal corner joint
- A vertical crack or gap where the extension meets the house
Extension pulling away repairs prices in Brent
For Brent 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 |
How we usually approach extension pulling away repairs
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
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
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 Brent
What is the price of extension pulling away repairs in Brent?
Guide prices for extension pulling away repairs in Brent 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 carry out extension pulling away repairs in Brent?
Yes. We take enquiries from across Brent, including HA0, HA9, NW9, NW10, and from nearby places such as Harrow and Ealing. Send photos for a free initial view and we will tell you what happens next.
Does the ground around Brent cause cracking?
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.
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.
What is a movement joint?
A movement joint is a deliberate, flexible break in a wall that lets two parts of a building move slightly without cracking. It is filled with a compressible material and sealed. At an extension junction it can replace a rigid joint that keeps cracking.
More repairs we carry out in Brent
- Subsidence insurance claim repairs
- Bowing wall repairs
- Crack stitching
- Retaining wall repairs
- Structural surveys and crack monitoring
Extension pulling away repairs near Brent
Photos of the crack, the internal corner and the roof flashing are a good start; send them about your Brent home and we will reply with a view.