Northamptonshire · England
Extension pulling away repairs in Northamptonshire
We arrange surveys and price extension pulling away repairs throughout Northamptonshire. Much of Northamptonshire sits on clay that shrinks in dry summers and swells in wet winters, and we take that into account before recommending a method.
Guide price from£590per junction inc VAT
- Area
- Northamptonshire
- Pricing region
- East Midlands
- Ground
- Shrinkable clay widespread
- Towns listed
- 6
Is Northamptonshire prone to ground movement?
Northamptonshire sits largely on Lias clay and Jurassic ironstones and limestones, with historic ironstone quarrying around Corby and Kettering. The clay vales are prone to shrinkage near trees.
Historic ironstone working has left disturbed ground in places. Typical buildings in Northamptonshire: Ironstone and limestone cottages, Victorian terraces in Northampton and Kettering, and new-town estates in Corby.
Symptoms that point to extension pulling away repairs
- A vertical crack or gap where the extension meets the house
- 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 Northamptonshire
Guide prices below are for homes in Northamptonshire, on East Midlands rates and including VAT. A survey or good photos let us turn them into a fixed written price.
| 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
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
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
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.
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.
Do you need approval 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.
Extension pulling away repairs near you in Northamptonshire
Frequently asked questions
Does the ground around Northampton cause cracking?
Northamptonshire sits largely on Lias clay and Jurassic ironstones and limestones, with historic ironstone quarrying around Corby and Kettering. The clay vales are prone to shrinkage near trees. Historic ironstone working has left disturbed ground in places. Only an investigation on site can say why a particular building has moved.
How much will extension pulling away repairs cost in Northamptonshire?
On East Midlands rates, extension pulling away repairs starts from about £590 per junction, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
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.
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.
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.