Caerphilly · Mid Glamorgan
Extension pulling away repairs in Caerphilly
If the corner joint in your Caerphilly extension keeps splitting after you fill it, something is still moving. Measuring the gap over a few months, with dated photos, gives an engineer the evidence to recommend the right repair.
Guide price from£550per junction inc VAT
- Postcodes
- CF83
- Population
- about 31,000
- Area
- Mid Glamorgan
- Pricing region
- Wales
How do local ground conditions affect extension pulling away repairs in Caerphilly?
Caerphilly, Mid Glamorgan: about 31,000 residents across postcode districts CF83. Nearby places we cover include Risca (6 miles), Pontypridd (6 miles) and Nelson (6 miles).
Parts of Mid Glamorgan have clay that can shrink near trees in dry spells. Historic coal workings are recorded beneath parts of Mid Glamorgan, and a coal mining search is worth checking where movement is unexplained. Typical buildings in Mid Glamorgan: Long stone and brick terraces on valley sides, Victorian houses in Bridgend and post-war estates.
Symptoms that point to extension pulling away repairs
- Extension roof flashing lifting off the original wall
- Daylight or draughts showing through the internal corner joint
- Floor level dropping where the extension and house floors meet
Guide prices for extension pulling away repairs in Caerphilly
Guide prices below are for homes in Caerphilly, on Wales rates and including VAT. A survey or good photos let us turn them into a fixed written price.
| Item | Guide price | Per |
|---|---|---|
| Junction crack repair with stainless tiesest. | £550 – £1,850 | per junction |
| Movement joint and making goodest. | £370 – £1,100 | per junction |
| Underpinning the extension where needed | £920 – £2,300 | per metre of wall |
Methods for extension pulling away repairs
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
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.
Rules for extension pulling away repairs in Wales
In Wales, the Welsh version of the Building Regulations applies. Underpinning and other work that alters or strengthens the structure needs building control approval and inspection; like-for-like repairs often do not. The Party Wall etc. Act 1996 applies to work on party walls and excavation close to a neighbour’s foundations.
Frequently asked questions
How much will extension pulling away repairs cost in Caerphilly?
Guide prices for extension pulling away repairs in Caerphilly start from about £550 per junction, including VAT, on Wales rates. Your fixed written price follows photos or a survey and depends on the extent of the work and access.
Do you cover Caerphilly?
Yes. We take enquiries from across Caerphilly, including CF83, and from nearby places such as Risca and Pontypridd. Send photos for a free initial view and we will tell you what happens next.
Is the ground in Mid Glamorgan prone to subsidence?
Mid Glamorgan lies on the South Wales coalfield, with dense historic workings, spoil tips and steep valley sides. Landslip, retaining walls and mining legacy are all live issues in the valleys. 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 Caerphilly
- Retaining wall repairs
- Subsidence insurance claim repairs
- Brick arch repairs
- Subsidence repairs
- Wall tie replacement
Extension pulling away repairs near Caerphilly
Photos of the crack, the internal corner and the roof flashing are a good start; send them about your Caerphilly home and we will reply with a view.