Cornwall · England
Concrete repairs in Cornwall
If you live in Cornwall and are looking at concrete repairs, the first question is why the wall moved. Shrinkable clay is less common in Cornwall than in south-east England; old metal-mine shafts and workings are recorded in places, so mining searches are routine for some properties.
Guide price from£90per m² 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. What you mostly find across Cornwall: granite and slate-stone cottages, cob buildings, Victorian terraces and post-war estates.
How we usually approach concrete repairs
Recasting or strengthening
Where steel has lost much of its section, or a lintel or canopy is too far gone to patch, the element is propped and rebuilt, replaced or strengthened to an engineer’s design. It is less common, but sometimes the more lasting option for small canopies and old precast lintels.
Best for: Badly corroded lintels, canopies and balcony edges
Patch repair
Loose and contaminated concrete is broken out behind the bar, the steel is cleaned of rust and primed, and the section is rebuilt with a repair mortar. The edges are cut square so the patch does not feather out and fail. A protective coating may be applied over the whole surface afterwards.
Best for: Localised spalling around rusting bars
Crack injection
Cracks are sealed at the surface, then a low-viscosity resin is injected under pressure through ports until it fills the crack. A rigid resin bonds the two faces back together, while a flexible one seals live cracks against water. The choice depends on whether the crack is still moving.
Best for: Cracks letting water in, or splitting a slab or beam
What happens during concrete repairs, step by step?
Photos and a description
Send photos of the damage close up and from a distance, plus the whole balcony, canopy or elevation. Tell us roughly how old the building is and whether anything has fallen, so we can judge whether to make it safe first.
Survey and tapping test
On site we tap the surface to find hollow areas, check the steel where it is exposed and note drainage. Where the extent is unclear, a cover meter, carbonation test or chloride test may be advised before repair.
Break out, repair, protect
Damaged concrete is cut back to sound material, steel cleaned and primed, and the section rebuilt and cured. Cracks are injected, then the surface is coated and drainage details put right so water runs off rather than sitting.
What to look for before calling about concrete repairs
- Fine cracks running in straight lines along the line of the reinforcement
- Damp patches, white deposits or drips on a balcony or canopy underside
- Rust-coloured stains or streaks running down the concrete surface
- Chunks or flakes of concrete breaking away from edges and soffits
Concrete repairs prices in Cornwall
Guide prices below are for homes in Cornwall, on South West rates and including VAT. A survey or good photos let us turn them into a fixed written price.
| Item | Guide price | Per |
|---|---|---|
| Concrete patch repair | £90 – £185 | per m² |
| Crack injection | £185 – £495 | per metre |
| Small jobs (minimum visit)est. | £465 – £925 | per visit |
Do you need approval for concrete repairs in England?
Like-for-like repairs such as crack stitching and repointing do not usually need building control approval in England, but anything that changes or strengthens the structure, such as underpinning or rebuilding a wall, does. If the work touches a party wall, the Party Wall etc. Act 1996 may apply.
Towns in Cornwall we cover for concrete repairs
Questions about concrete repairs in Cornwall
Is the ground in Cornwall prone to subsidence?
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 concrete repairs cost in Cornwall?
On South West rates, concrete repairs starts from about £90 per m², including VAT. The written price depends on the extent of the damage, access and whether an engineer or building control is needed.
What is carbonation in concrete?
Carbonation is the gradual reaction between carbon dioxide in the air and concrete, which lowers its alkalinity from the surface inward. Alkaline concrete protects the steel inside, so when carbonation reaches the bars, they can start to rust. A simple test on a freshly broken surface shows how deep it has gone.
Can you repair a cracked concrete lintel?
Often, yes. Spalling and small cracks in a concrete lintel can be patch repaired and the steel treated. If the lintel is badly cracked, sagging or the bars have lost much of their section, replacement is usually better, and the opening is propped while it is done.
Is spalling concrete dangerous?
It can be, mainly because pieces may fall from balconies, canopies and soffits above doors or paths. It also means the steel is losing strength over time. Fence off the area below any loose concrete, keep people off a balcony that is badly affected, and have it assessed soon.