Lancing · West Sussex
Extension pulling away repairs in Lancing
An extension pulling away from a Lancing 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£670per junction inc VAT

- Postcodes
- BN15
- Population
- about 19,000
- Area
- West Sussex
- Pricing region
- South East
What is the ground like in West Sussex?
Lancing, West Sussex: about 19,000 residents across postcode districts BN15. Nearby, we also cover Shoreham-by-Sea (2 miles), Worthing (2 miles) and Brighton (8 miles).
Much of West Sussex 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 West Sussex: Wealden cottages, 1930s semis and bungalows on the coast, and new-town estates in Crawley.
Symptoms that point to extension pulling away repairs
- Mastic or render at the joint repeatedly splitting open
- Floor level dropping where the extension and house floors meet
- Daylight or draughts showing through the internal corner joint
Guide prices for extension pulling away repairs in Lancing
For Lancing we use South East 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. | £670 – £2,250 | per junction |
| Movement joint and making goodest. | £450 – £1,350 | per junction |
| Underpinning the extension where needed | £1,100 – £2,800 | per metre of wall |
Methods for extension pulling away repairs
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
From first photo to finished repair
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.
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.
Frequently asked questions
What is the price of extension pulling away repairs in Lancing?
Guide prices for extension pulling away repairs in Lancing start from about £670 per junction, including VAT, on South East 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 Lancing?
We do. Lancing and the surrounding area are covered, including nearby Shoreham-by-Sea and Worthing. A free initial assessment from your photos is the first step.
Does the ground around Lancing cause cracking?
North West Sussex around Crawley and Horsham sits on Weald Clay, the South Downs are chalk, and the coastal plain has brickearth and gravels. The Weald Clay is prone to shrink-swell movement near trees. Only an investigation can say why a particular building has moved.
Can I just fill the gap with mastic?
Mastic can keep water out short term, but it does not stop movement or reconnect the walls. If the gap reopens after filling, something is still moving. Photograph and measure it over a few months first, so an engineer can see the trend.
Why is my extension pulling away from my house?
Usually because the extension and the house sit on different foundations that react differently to the ground. Shallow extension footings, leaking drains under the extension, nearby roots and weak tie-ins between old and new walls are the common causes.
More repairs we carry out in Lancing
- Bowing wall repairs
- Gable end wall repairs
- Crack stitching
- Retaining wall repairs
- Resin injection ground stabilisation
Extension pulling away repairs near Lancing
Call about the cracked extension junction at your Lancing property; a free initial assessment first, then a fixed written price once the repair is specified.