South Glamorgan · Wales
Subsidence repairs in South Glamorgan
Subsidence repairs in South Glamorgan starts with the ground. Clay soils are found in parts of South Glamorgan, and the buildings here are mostly Victorian terraces in Cardiff and Penarth, so the repair has to suit both.
Guide price from£2,300per property inc VAT
- Area
- South Glamorgan
- Pricing region
- Wales
- Ground
- Clay in parts
- Towns listed
- 4
How do local ground conditions affect subsidence repairs in South Glamorgan?
Cardiff is built on Mercia Mudstone, river gravels and alluvium, and the Vale of Glamorgan on Lias limestone and clay. Soft alluvium near the rivers and docks can settle.
Ground movement here is more often linked to soils, drains and trees than to mining. Across South Glamorgan, most homes are Victorian terraces in Cardiff and Penarth, inter-war semis and post-war estates.
Signs you may need subsidence repairs
- Diagonal cracks wider at the top, running from window or door corners
- Doors and windows that start to stick or no longer close
- Wallpaper rippling or tearing where the wall meets the ceiling
- A gap opening between the skirting board and the floor
How much will subsidence repairs cost in South Glamorgan?
For South Glamorgan we use Wales rates. Treat the table as a budget guide, inc VAT; the price you pay is the one on your written quote.
| Item | Guide price | Per |
|---|---|---|
| Structural engineer's investigation and report | £460 – £1,850 | per property |
| CCTV drain survey (common first check) | £140 – £320 | per survey |
| Typical repair once the cause is dealt with: crack stitching and making goodest. | £2,300 – £11,000 | per property |
| Foundation strengthening where it is needed (see underpinning) | £920 – £3,200 | per metre of wall |
Which repair method suits a home in South Glamorgan?
Remove the cause, then repair
Most subsidence is dealt with this way. The drain is repaired or the vegetation managed, the house is watched to confirm it has stabilised, and then the cracks are stitched, repointed and made good inside. It is the least disruptive route and usually the cheapest.
Best for: Clay movement or drain leaks where the cause can be removed
Crack stitching and making good
Once movement has stopped, cracked brickwork is cut along the bed joints, stainless helical bars are bonded in to tie the wall together, and the joints are repointed to match. Inside, plaster is renewed along the crack line before redecoration.
Best for: Category 1 to 3 cracking in walls that are otherwise sound
Foundation strengthening
Where the ground cannot be made stable, the load is carried down to firmer soil by underpinning, a beam-and-base scheme, mini-piles or resin injection, depending on the soil and access. It is designed by an engineer and is the exception, not the rule.
Best for: Ongoing movement where removing the cause has not worked
What happens when we carry out subsidence repairs in South Glamorgan?
Find the cause
An independent chartered structural engineer inspects the house and, where needed, arranges a drain survey, trial pits or soil tests. We can arrange the engineer. The aim is to know what is moving, and why, before money goes on repairs.
Written quote
We price the agreed repair and confirm a fixed price in writing once it is specified. If there is an insurance claim, we can price to the loss adjuster’s or engineer’s schedule instead of our own scope.
Repairs and making good
Cracks are stitched and repointed outside, plaster is renewed along the crack lines inside, and sticking doors are eased. Where the work needs it, we deal with building control and hand over the paperwork.
Do you need approval for subsidence 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.
Find subsidence repairs in your South Glamorgan town
Subsidence repairs in South Glamorgan: questions and answers
Why do houses in South Glamorgan crack?
Cardiff is built on Mercia Mudstone, river gravels and alluvium, and the Vale of Glamorgan on Lias limestone and clay. Soft alluvium near the rivers and docks can settle. Ground movement here is more often linked to soils, drains and trees than to mining. Only an investigation on site can say why a particular building has moved.
How much will subsidence repairs cost in South Glamorgan?
On Wales rates, subsidence repairs starts from about £2,300 per property, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
Should I cut down the tree near my house?
Not without advice, because felling a mature tree on clay can make things worse. As the roots stop drawing water, the clay swells and can lift the foundations, which is called heave. Pruning or staged removal may be advised instead. Check whether the tree is protected.
Can I sell a house that has had subsidence?
Yes, though buyers and lenders will want paperwork. Keep the engineer’s report, monitoring results, the repair specification and any building control sign-off. A repaired house shown to be stable is far easier to sell than one with an open problem.
How long should I wait before repairing subsidence cracks?
Usually until the cause has been dealt with and the engineer is satisfied that movement has stopped. On clay that can mean watching the house through a summer and a winter. Repairing too early risks the same cracks opening again.