Marlow · Buckinghamshire
Extension pulling away repairs in Marlow
For many Marlow 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£670per junction inc VAT

- Postcodes
- SL7
- Population
- about 18,000
- Area
- Buckinghamshire
- Pricing region
- South East
What should you know about the ground under Marlow?
Postcode districts SL7 cover Marlow, a Buckinghamshire town of about 18,000 people. If you are just outside Marlow, we also cover Maidenhead (4 miles), High Wycombe (4 miles) and Slough (9 miles).
Shrinkable clay is widespread in Buckinghamshire. Ground movement here is more often linked to soils, drains and trees than to mining. Typical buildings in Buckinghamshire: Market-town terraces, 1930s semis in the south, and large late-20th-century estates in Milton Keynes and Aylesbury.
Extension pulling away repairs prices in Marlow
The ranges below reflect typical South East costs for extension pulling away repairs, including VAT. Scaffold, access and making good can push a job to the top of the range.
| 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 |
How we usually approach 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
Underpinning the extension
If the extension is still dropping because its footings are too shallow or on poor ground, they are taken deeper by mass concrete, beam-and-base or mini-piles. The engineer designs the scheme, and the junction is repaired once the new foundation is in.
Best for: Active movement from shallow footings, roots or soft ground
What happens during extension pulling away repairs, step by step?
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.
What to look for before calling about extension pulling away repairs
- A vertical crack or gap where the extension meets the house
- Daylight or draughts showing through the internal corner joint
- Extension roof flashing lifting off the original 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.
Questions about extension pulling away repairs in Marlow
How much should I budget for extension pulling away repairs in Marlow?
Guide prices for extension pulling away repairs in Marlow 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 Marlow?
Yes, Marlow is covered, along with postcode districts SL7. We also cover nearby Maidenhead and High Wycombe.
Why do houses in Buckinghamshire crack?
The Chilterns are chalk with clay-with-flints on the tops, while the Vale of Aylesbury and Milton Keynes sit on Gault, Kimmeridge and Oxford Clays and glacial till. The vale clays are prone to seasonal shrinkage near trees. Only an investigation can say why a particular building has moved.
Who is responsible if a recent extension is moving?
If the extension is recent, the original builder, the designer or building control records may be relevant, and you may have rights against the builder. Gather the plans, completion certificate and contract. Insurance often excludes defects in new construction, so check your policy.
What is a movement joint?
A movement joint is a deliberate, flexible break in a wall that lets two parts of a building move slightly without cracking. It is filled with a compressible material and sealed. At an extension junction it can replace a rigid joint that keeps cracking.
Related work in Marlow
- Floor joist repairs
- Retaining wall repairs
- Bay window subsidence repairs
- Boundary and garden wall repairs
- Wall tie replacement
Extension pulling away repairs near Marlow
Call about the cracked extension junction at your Marlow property; a free initial assessment first, then a fixed written price once the repair is specified.