Derby · Derbyshire
Extension pulling away repairs in Derby
If the corner joint in your Derby 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£590per junction inc VAT

- Postcodes
- DE1, DE22, DE23
- Population
- about 270,000
- Area
- Derbyshire
- Pricing region
- East Midlands
Is Derbyshire prone to ground movement?
We cover Derby and its postcode districts DE1, DE22, DE23, part of Derbyshire, with a population of roughly 270,000. Neighbouring towns we cover: Belper (7 miles), Ilkeston (8 miles) and Heanor (8 miles).
Derbyshire has a mix of ground, with clay in some places and firmer rock in others. Parts of Derbyshire lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. Typical buildings in Derbyshire: Brick terraces in former mining towns, gritstone cottages in the Peak, and inter-war and post-war semis.
Guide prices for extension pulling away repairs in Derby
Prices in Derby are worked out on East Midlands rates. They include VAT and are a starting point: access, the extent of the damage and whether an engineer or building control is involved all move the figure.
| Item | Guide price | Per |
|---|---|---|
| Junction crack repair with stainless tiesest. | £590 – £1,950 | per junction |
| Movement joint and making goodest. | £390 – £1,200 | per junction |
| Underpinning the extension where needed | £980 – £2,450 | per metre of wall |
Methods for 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
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
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.
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.
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.
Symptoms that point to extension pulling away repairs
- A vertical crack or gap where the extension meets the house
- Floor level dropping where the extension and house floors meet
- Extension roof flashing lifting off the original wall
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 Derby?
Guide prices for extension pulling away repairs in Derby start from about £590 per junction, including VAT, on East Midlands rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Derby?
Yes, Derby is covered, along with postcode districts DE1, DE22, DE23. We also cover nearby Belper and Ilkeston.
Is the ground in Derbyshire prone to subsidence?
East Derbyshire, including Chesterfield, Ilkeston and Heanor, lies on the Coal Measures with a long history of shallow and deep coal mining. The Peak District to the west is limestone and gritstone, and Derby itself sits largely on Mercia Mudstone. 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.
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.
Other structural repairs in Derby
- Wall tie replacement
- Structural surveys and crack monitoring
- Subsidence insurance claim repairs
- Bay window subsidence repairs
- Resin injection ground stabilisation
Extension pulling away repairs near Derby
If the junction at your Derby property keeps reopening, send dated photos and we will suggest whether monitoring, a drain survey or a repair comes next.