Wellingborough · Northamptonshire
Extension pulling away repairs in Wellingborough
The ground under Wellingborough and Northamptonshire varies street by street, and extensions built on shallower footings feel those differences first. A trial pit and a drain survey usually tell an engineer how the extension’s foundation is coping.
Guide price from£590per junction inc VAT

- Postcodes
- NN8
- Population
- about 57,000
- Area
- Northamptonshire
- Pricing region
- East Midlands
What should you know about the ground under Wellingborough?
We cover Wellingborough and its postcode districts NN8, part of Northamptonshire, with a population of roughly 57,000. Nearby, we also cover Rushden (4 miles), Kettering (7 miles) and Northampton (9 miles).
Northamptonshire is one of the parts of the UK where clay soils are most likely to move with the seasons. Historic ironstone working has left disturbed ground in places. What you mostly find across Northamptonshire: ironstone and limestone cottages, Victorian terraces in Northampton and Kettering, and new-town estates in Corby.
What should you budget for extension pulling away repairs in Wellingborough?
For Wellingborough we use East Midlands 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. | £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 |
Repair options we may recommend
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
What to expect when we carry out extension pulling away repairs
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.
Is it time for extension pulling away repairs? Common signs
- Mastic or render at the joint repeatedly splitting open
- A vertical crack or gap where the extension meets the house
- Patio doors or windows in the extension starting to bind
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.
Your extension pulling away repairs questions
How much should I budget for extension pulling away repairs in Wellingborough?
Guide prices for extension pulling away repairs in Wellingborough 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.
Can you survey a property in Wellingborough?
Yes, Wellingborough is covered, along with postcode districts NN8. We also cover nearby Rushden and Kettering.
Why do houses in Northamptonshire crack?
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. 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.
Related work in Wellingborough
- Floor joist repairs
- Crack stitching
- Boundary and garden wall repairs
- Roof structure repairs
- Subsidence insurance claim repairs
Extension pulling away repairs near Wellingborough
Photos of the crack, the internal corner and the roof flashing are a good start; send them about your Wellingborough home and we will reply with a view.