Stevenage · Hertfordshire
Extension pulling away repairs in Stevenage
For many Stevenage homes, the extension was added decades after the house was built, on concrete that never matched the original footings. Where that difference causes movement, a designed movement joint or a deeper foundation is the usual fix.
Guide price from£630per junction inc VAT
- Postcodes
- SG1, SG2
- Population
- about 92,000
- Area
- Hertfordshire
- Pricing region
- East of England
How do local ground conditions affect extension pulling away repairs in Stevenage?
Stevenage is in Hertfordshire and takes in postcode districts SG1, SG2. About 92,000 people live there. If you are just outside Stevenage, we also cover Hitchin (5 miles), Letchworth Garden City (5 miles) and Welwyn Garden City (7 miles).
Hertfordshire is one of the parts of the UK where clay soils are most likely to move with the seasons. Ground movement here is more often linked to soils, drains and trees than to mining. What you mostly find across Hertfordshire: garden-city houses in Letchworth and Welwyn, 1930s semis, Victorian terraces and post-war new-town estates.
From first photo to finished repair
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.
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.
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
- Floor level dropping where the extension and house floors meet
- Mastic or render at the joint repeatedly splitting open
- Extension roof flashing lifting off the original wall
Guide prices for extension pulling away repairs in Stevenage
Prices in Stevenage are worked out on East of England 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. | £630 – £2,100 | per junction |
| Movement joint and making goodest. | £420 – £1,250 | per junction |
| Underpinning the extension where needed | £1,050 – £2,600 | per metre of wall |
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
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 should I budget for extension pulling away repairs in Stevenage?
Guide prices for extension pulling away repairs in Stevenage start from about £630 per junction, including VAT, on East of England 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 Stevenage?
Yes. We take enquiries from across Stevenage, including SG1, SG2, and from nearby places such as Hitchin and Letchworth Garden City. Send photos for a free initial view and we will tell you what happens next.
Why do houses in Hertfordshire crack?
South Hertfordshire around Watford, Borehamwood and Potters Bar is London Clay, while the north and west are chalk with clay-with-flints and the east has boulder clay. The clay areas are prone to seasonal subsidence near 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.
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.
Related work in Stevenage
- Subsidence insurance claim repairs
- Concrete repairs
- Structural crack repairs
- Resin injection ground stabilisation
- Brick arch repairs
Extension pulling away repairs near Stevenage
Photos of the crack, the internal corner and the roof flashing are a good start; send them about your Stevenage home and we will reply with a view.