Wandsworth · Greater London
Extension pulling away repairs in Wandsworth
Rear and side extensions are common across Wandsworth, and so is the crack where new meets old. Usually it reflects the two parts sitting on different foundations, and the first question is whether the gap is still opening.
Guide price from£750per junction inc VAT
- Postcodes
- SW6, SW11, SW15, SW17, SW18
- Population
- about 330,000
- Area
- Greater London
- Pricing region
- London
Is Greater London prone to ground movement?
Wandsworth takes in postcode districts including SW6, SW11, SW15, SW17, SW18, with about 330,000 residents. If you are just outside Wandsworth, we also cover Hammersmith and Fulham (3 miles), Lambeth (3 miles) and Kensington and Chelsea (3 miles).
Shrinkable clay is widespread in Greater London. Ground movement here is more often linked to soils, drains and trees than to mining. Across Greater London, most homes are Victorian and Edwardian terraces with shallow footings, inter-war semis in the outer boroughs, and converted flats and mansion blocks.
What happens when we carry out extension pulling away repairs in Wandsworth?
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.
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.
Signs you may need 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
- Mastic or render at the joint repeatedly splitting open
How much will extension pulling away repairs cost in Wandsworth?
Prices in Wandsworth are worked out on London 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. | £750 – £2,500 | per junction |
| Movement joint and making goodest. | £500 – £1,500 | per junction |
| Underpinning the extension where needed | £1,250 – £3,100 | per metre of wall |
Which repair method suits a home in Wandsworth?
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
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
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.
Extension pulling away repairs in Wandsworth: questions and answers
How much will extension pulling away repairs cost in Wandsworth?
Guide prices for extension pulling away repairs in Wandsworth start from about £750 per junction, including VAT, on London rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Wandsworth?
Yes. We take enquiries from across Wandsworth, including SW6, SW11, SW15, SW17, and from nearby places such as Hammersmith and Fulham and Lambeth. Send photos for a free initial view and we will tell you what happens next.
Is the ground in Greater London prone to subsidence?
Most of Greater London sits on London Clay, among the most shrinkage-prone ground in the UK, with river gravels along the Thames. Subsidence claims here are among the most frequent in the country, especially after dry summers and near street and garden trees. 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.
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 Wandsworth
- Brick arch repairs
- Crack stitching
- Structural crack repairs
- Boundary and garden wall repairs
- Floor joist repairs
Extension pulling away repairs near Wandsworth
If the junction at your Wandsworth property keeps reopening, send dated photos and we will suggest whether monitoring, a drain survey or a repair comes next.