Gwynedd · Wales
Concrete repairs in Gwynedd
If you live in Gwynedd and are looking at concrete repairs, the first question is why the wall moved. Shrinkable clay is less common in Gwynedd 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£80per m² inc VAT

- Area
- Gwynedd
- Pricing region
- Wales
- Ground
- Mostly firmer ground
- Towns listed
- 6
Is Gwynedd prone to ground movement?
Gwynedd and Anglesey are mostly hard rock with glacial deposits, so clay shrinkage is uncommon. Historic slate quarrying and metal mining have left tips and workings in places.
Old metal-mine shafts and workings are recorded in places, so mining searches are routine for some properties. Housing stock in Gwynedd: Slate and stone terraces, chapels and cottages, Victorian seaside houses 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
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
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
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.
Engineer where needed
If the steel has lost significant section, or the element carries a balcony, stair or wall, an independent chartered structural engineer is appointed to assess and specify. We can arrange this, and the repair follows their scope.
Written quote
You receive a no-obligation written quote setting out the estimated area of patching, the length of crack injection, coatings and access. It becomes a fixed price in writing once the repair is specified, with any re-measure terms stated clearly.
What to look for before calling about concrete repairs
- Hollow sound when the surface is tapped with a hammer
- Chunks or flakes of concrete breaking away from edges and soffits
- Exposed steel bars showing where concrete has fallen away
- Damp patches, white deposits or drips on a balcony or canopy underside
Concrete repairs prices in Gwynedd
Guide prices below are for homes in Gwynedd, on Wales 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 | £80 – £165 | per m² |
| Crack injection | £165 – £440 | per metre |
| Small jobs (minimum visit)est. | £415 – £830 | per visit |
Do you need approval for concrete repairs in Wales?
In Wales, small like-for-like repairs do not usually need approval, but work that alters or strengthens the structure needs building control under the Welsh Building Regulations, and the Party Wall etc. Act 1996 can apply to shared walls.
Towns in Gwynedd we cover for concrete repairs
Questions about concrete repairs in Gwynedd
Is the ground in Gwynedd prone to subsidence?
Gwynedd and Anglesey are mostly hard rock with glacial deposits, so clay shrinkage is uncommon. Historic slate quarrying and metal mining have left tips and workings in places. 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 Gwynedd?
On Wales rates, concrete repairs starts from about £80 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 spalling concrete?
Spalling is concrete breaking away from the surface in flakes or chunks. In reinforced concrete it is usually caused by the steel inside rusting and expanding, which pushes the cover off. It often follows a straight line where a bar sits close to the surface, with rust staining nearby.
Can a concrete balcony be repaired rather than replaced?
In most cases, yes. Patch repairs, crack injection, a new waterproof deck and restored drips usually extend a balcony’s life considerably. Replacement is generally only needed where the steel has lost a lot of section or the balcony’s fixing to the building is compromised.
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.