Cornwall · England
Subsidence repairs in Cornwall
Across Cornwall, requests for subsidence repairs usually begin with a crack someone has noticed getting wider. Shrinkable clay is less common in Cornwall than in south-east England. A repair only lasts if the reason for the movement has stopped.
Guide price from£2,600per property inc VAT
- Area
- Cornwall
- Pricing region
- South West
- Ground
- Mostly firmer ground
- Towns listed
- 9
What is the ground like in Cornwall?
Cornwall is mostly granite and slate with little shrinkable clay, so clay subsidence is less common than in the south-east. Historic tin and copper mining has left shafts and workings in places such as Camborne and Redruth, and mining searches are routine there.
Old metal-mine shafts and workings are recorded in places, so mining searches are routine for some properties. Across Cornwall, most homes are granite and slate-stone cottages, cob buildings, Victorian terraces and post-war estates.
Is it time for subsidence repairs? Common signs
- Diagonal cracks wider at the top, running from window or door corners
- A gap opening between the skirting board and the floor
- Doors and windows that start to stick or no longer close
- Fresh cracks showing on both the inside and outside of one wall
What should you budget for subsidence repairs in Cornwall?
These are guide prices for Cornwall, 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 |
|---|---|---|
| Structural engineer's investigation and report | £515 – £2,050 | per property |
| CCTV drain survey (common first check) | £155 – £360 | per survey |
| Typical repair once the cause is dealt with: crack stitching and making goodest. | £2,600 – £12,400 | per property |
| Foundation strengthening where it is needed (see underpinning) | £1,050 – £3,600 | per metre of wall |
Repair options we may recommend
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
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
What to expect when we carry out subsidence repairs
Send photos or call
Send photos of the cracks with a coin or tape for scale, and say when you first noticed them. We give a free initial assessment and suggest whether an engineer, a drain survey or your insurer comes first.
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.
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 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.
Find subsidence repairs in your Cornwall town
Your subsidence repairs questions
Why do houses in Cornwall crack?
Cornwall is mostly granite and slate with little shrinkable clay, so clay subsidence is less common than in the south-east. Historic tin and copper mining has left shafts and workings in places such as Camborne and Redruth, and mining searches are routine there. Old metal-mine shafts and workings are recorded in places, so mining searches are routine for some properties. Only an investigation on site can say why a particular building has moved.
How much will subsidence repairs cost in Cornwall?
On South West rates, subsidence repairs starts from about £2,600 per property, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
Will past subsidence affect my home insurance?
It can, because insurers ask about previous subsidence at renewal or when you switch. Staying with the insurer who handled a claim is often simplest. Answer any new insurer’s questions honestly and keep the repair records, which show the problem was dealt with.
Do you need to visit before giving a price?
Not at first. We give a free initial assessment from your photos or a call, and a no-obligation written quote once the scope is clear. A fixed price follows in writing once the repair is specified, which normally needs a survey.
Does subsidence always need underpinning?
No, most subsidence is repaired without underpinning. When a leaking drain is fixed or nearby vegetation is managed, the ground usually stabilises and the house needs only crack repairs. Foundation work is kept for movement that continues after the cause has gone.