Keynsham · Somerset
Extension pulling away repairs in Keynsham
Rear and side extensions are common across Keynsham, 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£620per junction inc VAT

- Postcodes
- BS31
- Population
- about 20,000
- Area
- Somerset
- Pricing region
- South West
Is Somerset prone to ground movement?
With roughly 20,000 people, Keynsham spans postcode districts BS31 in Somerset. Nearby, we also cover Kingswood (3 miles), Bath (6 miles) and Yate (9 miles).
Clay soils are found in parts of Somerset. Parts of Somerset lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. Typical buildings in Somerset: Bath stone Georgian terraces, Victorian houses in Taunton and Weston-super-Mare, and post-war estates.
What to expect when we carry out extension pulling away repairs
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.
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
- Floor level dropping where the extension and house floors meet
- Extension roof flashing lifting off the original wall
- A vertical crack or gap where the extension meets the house
What should you budget for extension pulling away repairs in Keynsham?
These are guide prices for Keynsham, using South West 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. | £620 – £2,050 | per junction |
| Movement joint and making goodest. | £410 – £1,250 | per junction |
| Underpinning the extension where needed | £1,050 – £2,600 | per metre of wall |
Repair options we may recommend
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
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.
Your extension pulling away repairs questions
How much will extension pulling away repairs cost in Keynsham?
Guide prices for extension pulling away repairs in Keynsham start from about £620 per junction, including VAT, on South West rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Keynsham?
Yes, Keynsham is covered, along with postcode districts BS31. We also cover nearby Kingswood and Bath.
Is the ground in Somerset prone to subsidence?
Somerset mixes Lias clays, Mercia Mudstone, limestone hills and the peat and alluvium of the Levels around Bridgwater, which can settle. The former Somerset coalfield around Radstock and Midsomer Norton left recorded workings. Only an investigation can say why a particular building has moved.
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.
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.
Other structural repairs in Keynsham
- Subsidence repairs
- Mining subsidence repairs
- Roof structure repairs
- Bay window subsidence repairs
- Floor joist repairs
Extension pulling away repairs near Keynsham
Call about the cracked extension junction at your Keynsham property; a free initial assessment first, then a fixed written price once the repair is specified.