Tonbridge · Kent
Extension pulling away repairs in Tonbridge
If the corner joint in your Tonbridge 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
- TN9, TN10, TN11
- Population
- about 36,000
- Area
- Kent
- Pricing region
- South East
What is the ground like in Kent?
With roughly 36,000 people, Tonbridge spans postcode districts TN9, TN10, TN11 in Kent. Neighbouring towns we cover: Tunbridge Wells (4 miles), Sevenoaks (6 miles) and Crowborough (10 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.
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
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.
Symptoms that point to extension pulling away repairs
- Patio doors or windows in the extension starting to bind
- Mastic or render at the joint repeatedly splitting open
- Daylight or draughts showing through the internal corner joint
Guide prices for extension pulling away repairs in Tonbridge
These are guide prices for Tonbridge, using South East rates and including VAT. Your written quote follows photos or a survey, and is fixed once the repair is specified.
| 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.
Frequently asked questions
How much will extension pulling away repairs cost in Tonbridge?
Guide prices for extension pulling away repairs in Tonbridge 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 Tonbridge?
Yes, Tonbridge is covered, along with postcode districts TN9, TN10, TN11. We also cover nearby Tunbridge Wells and Sevenoaks.
Is the ground in Kent prone to subsidence?
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.
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.
Other structural repairs in Tonbridge
Extension pulling away repairs near Tonbridge
Send photos of the extension junction at your Tonbridge home, inside and out, and we will give a free initial assessment and a guide price.