Brighton · East Sussex
Extension pulling away repairs in Brighton
If the corner joint in your Brighton 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£670per junction inc VAT
- Postcodes
- BN1, BN2, BN3, BN41
- Population
- about 280,000
- Area
- East Sussex
- Pricing region
- South East
Is East Sussex prone to ground movement?
Brighton, East Sussex: about 280,000 residents across postcode districts BN1, BN2, BN3, BN41. Neighbouring towns we cover: Shoreham-by-Sea (6 miles), Peacehaven (6 miles) and Lewes (7 miles).
Shrinkable clay is widespread in East Sussex. Ground movement here is more often linked to soils, drains and trees than to mining. Across East Sussex, most homes are Regency and Victorian terraces on the coast, Wealden timber-framed houses, and inter-war bungalows and semis.
Symptoms that point to extension pulling away repairs
- Mastic or render at the joint repeatedly splitting open
- Patio doors or windows in the extension starting to bind
- A vertical crack or gap where the extension meets the house
Guide prices for extension pulling away repairs in Brighton
For Brighton 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
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
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
From first photo to finished repair
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.
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.
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
How much will extension pulling away repairs cost in Brighton?
Guide prices for extension pulling away repairs in Brighton 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 cover Brighton?
Yes, Brighton is covered, along with postcode districts BN1, BN2, BN3, BN41. We also cover nearby Shoreham-by-Sea and Peacehaven.
Is the ground in East Sussex prone to subsidence?
Inland East Sussex is Weald Clay and Wealden sands, while the South Downs and the coast around Brighton and Eastbourne are chalk. The Weald Clay areas are prone to shrink-swell movement near trees. Only an investigation can say why a particular building has moved.
Is it normal for an extension to crack at the join?
A fine crack at the junction is fairly common, especially in the first few years as a new extension settles. It becomes a concern when the gap is widening, tapering, letting in water or matched by sticking doors and sloping floors. Those signs point to continuing movement.
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.
Other structural repairs in Brighton
- Structural surveys and crack monitoring
- Bay window subsidence repairs
- Chimney stack repairs
- Retaining wall repairs
- Floor joist repairs
Extension pulling away repairs near Brighton
Photos of the crack, the internal corner and the roof flashing are a good start; send them about your Brighton home and we will reply with a view.