Canterbury · Kent
Extension pulling away repairs in Canterbury
The ground under Canterbury and Kent 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£670per junction inc VAT

- Postcodes
- CT1, CT2, CT5, CT6
- Population
- about 55,000
- Area
- Kent
- Pricing region
- South East
How do local ground conditions affect extension pulling away repairs in Canterbury?
Postcode districts CT1, CT2, CT5, CT6 cover Canterbury, a Kent town of about 55,000 people. Nearby, we also cover Whitstable (6 miles), Herne Bay (7 miles) and Faversham (9 miles).
Much of Kent sits on clay that shrinks in dry summers and swells in wet winters. Parts of Kent lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. Across Kent, most homes are Victorian terraces in the Medway towns, weatherboarded and Wealden houses, 1930s semis and seaside bungalows.
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.
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.
Is it time for extension pulling away repairs? Common signs
- Daylight or draughts showing through the internal corner joint
- Mastic or render at the joint repeatedly splitting open
- Extension roof flashing lifting off the original wall
What should you budget for extension pulling away repairs in Canterbury?
For Canterbury 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 |
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 Canterbury?
Guide prices for extension pulling away repairs in Canterbury 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.
Can you survey a property in Canterbury?
Yes. We take enquiries from across Canterbury, including CT1, CT2, CT5, CT6, and from nearby places such as Whitstable and Herne Bay. Send photos for a free initial view and we will tell you what happens next.
Why do houses in Kent crack?
North Kent sits on London Clay, central Kent on Gault and Weald Clays and the Downs on chalk, so shrinkable clay is widespread. East Kent around Deal and Dover had a small deep coalfield, worked until the late 1980s. 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.
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 Canterbury
- Boundary and garden wall repairs
- Resin injection ground stabilisation
- Lintel replacement
- Floor joist repairs
- Subsidence insurance claim repairs
Extension pulling away repairs near Canterbury
If the junction at your Canterbury property keeps reopening, send dated photos and we will suggest whether monitoring, a drain survey or a repair comes next.