Extension pulling away repairs in Lancashire

Area: Lancashire
Pricing region: North West
Ground: Clay in parts
Towns listed: 20

How do local ground conditions affect extension pulling away repairs in Lancashire?

Parts of Lancashire lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. Housing stock in Lancashire: Stone and brick mill terraces, seaside villas in Blackpool and Lytham, and inter-war and post-war semis.

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

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

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

Daylight or draughts showing through the internal corner joint
Mastic or render at the joint repeatedly splitting open
Floor level dropping where the extension and house floors meet
A vertical crack or gap where the extension meets the house

Guide prices for extension pulling away repairs in Lancashire

Prices in Lancashire are worked out on North West 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.

Guide prices inc VAT on North West rates. Items marked est. are our estimates.
Item	Guide price	Per
Junction crack repair with stainless tiesest.	£575 – £1,900	per junction
Movement joint and making goodest.	£385 – £1,150	per junction
Underpinning the extension where needed	£960 – £2,400	per metre of wall

Extension pulling away: tapered gap at the junction tied in with stainless bars. Indicative drawing, not to scale.

Do you need approval 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.

Towns in Lancashire we cover for extension pulling away repairs

Frequently asked questions

Is the ground in Lancashire prone to subsidence?

Lancashire is mostly glacial till over sandstone and mudstone, with the Burnley and Accrington coalfield in the east and soft coastal and estuarine ground on the Fylde. Old mill and mine sites leave made ground in many towns. Parts of Lancashire lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. Only an investigation on site can say why a particular building has moved.

How much will extension pulling away repairs cost in Lancashire?

On North West rates, extension pulling away repairs starts from about £575 per junction, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.

Can a drain under my extension cause it to move?

Yes, a cracked or displaced drain beneath or beside an extension can soften clay or wash away fine soil. A CCTV drain survey usually finds it. Repairing the drain is often the first and most important step before any repair to the walls.

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.