Kent · England
Subsidence repairs in Kent
We arrange surveys and price subsidence repairs throughout Kent. Shrinkable clay is widespread in Kent, and we take that into account before recommending a method.
Guide price from£2,800per property inc VAT
- Area
- Kent
- Pricing region
- South East
- Ground
- Shrinkable clay widespread
- Towns listed
- 22
Why does the ground in Kent matter for subsidence repairs?
North Kent sits on London Clay, central Kent on Gault and Weald Clays and the Downs on chalk, so shrinkable clay is widespread. East Kent around Deal and Dover had a small deep coalfield, worked until the late 1980s.
Parts of Kent lie on a former coalfield, so a coal mining search is worth checking if movement has no obvious cause. What you mostly find across Kent: Victorian terraces in the Medway towns, weatherboarded and Wealden houses, 1930s semis and seaside bungalows.
From first photo to finished repair
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.
Symptoms that point to subsidence repairs
- A gap opening between the skirting board and the floor
- Cracks that open in summer and partly close again in winter
- Doors and windows that start to stick or no longer close
- Fresh cracks showing on both the inside and outside of one wall
Guide prices for subsidence repairs in Kent
Prices in Kent are worked out on South East 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.
| Item | Guide price | Per |
|---|---|---|
| Structural engineer's investigation and report | £560 – £2,250 | per property |
| CCTV drain survey (common first check) | £170 – £390 | per survey |
| Typical repair once the cause is dealt with: crack stitching and making goodest. | £2,800 – £13,400 | per property |
| Foundation strengthening where it is needed (see underpinning) | £1,100 – £3,900 | per metre of wall |
Methods for subsidence repairs
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
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
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
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 Kent town
- Maidstone
- Gillingham
- Tunbridge Wells
- Folkestone
- Margate
- Ashford
- Canterbury
- Sittingbourne
- Gravesend
- Dartford
- Ramsgate
- Dover
- Tonbridge
- Strood
- Whitstable
- Deal
- Sevenoaks
- Herne Bay
- Faversham
- Swanley
- Longfield
- Swanscombe
Frequently asked questions
Why do houses in Kent crack?
North Kent sits on London Clay, central Kent on Gault and Weald Clays and the Downs on chalk, so shrinkable clay is widespread. East Kent around Deal and Dover had a small deep coalfield, worked until the late 1980s. Parts of Kent 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 subsidence repairs cost in Kent?
On South East rates, subsidence repairs starts from about £2,800 per property, including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
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.
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.
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.