How Much Does Concrete Spalling Repair Cost? UK Commercial Price Guide 2026

What Determines the Cost of Concrete Spalling Repair?

Concrete spalling repair is one of the most frequently requested services in commercial building maintenance, and it is also one of the most difficult to price without a detailed condition survey. The cost of repairing spalled concrete on a commercial structure is driven by four principal variables: the extent and depth of the spalling; the cause of the spalling and whether it needs to be addressed as well as the physical repair; the access required to reach the affected areas; and the specification of the repair system in terms of strength class, carbonation resistance and surface finish requirement.

A building manager who has noticed spalling on an exposed soffit, a column base or an external wall face should understand from the outset that the visible area of spalling is almost always smaller than the area of concrete that is sufficiently deteriorated to require repair — typically by a factor of 1.5 to 3 times. The visible spall is the point where cover concrete has already fallen; the surrounding concrete may be delaminated, cracked or carbonated to a depth that renders it structurally inadequate or aesthetically unacceptable within a short time frame. A thorough survey — including phenolphthalein testing for carbonation depth, half-cell potential mapping for corrosion risk, and cover measurements — is therefore essential before any repair contract is priced or let.

MPS Concrete Solutions provides condition surveys and spalling repair programmes for commercial and industrial structures across London and the South East. Our detailed guide to Concrete Spalling Repair covers the causes, diagnosis and repair options in depth. The cost guidance in this article is intended to support preliminary budget planning and to help building managers challenge quotations; it does not substitute for a site-specific assessment.

Indicative Cost Ranges for Commercial Spalling Repair in 2026

The following ranges represent typical UK market pricing for commercial concrete spalling repair in 2026, based on our project experience. All figures exclude VAT, scaffold or access equipment, and any enabling works required to gain access to the repair area. They assume the cause of spalling has been identified and — where it is an ongoing process such as carbonation, chloride ingress or a leaking expansion joint — that the cause is being addressed concurrently with the physical repair.

For shallow spalling with cover depths of 15–30 mm over corroded reinforcement on accessible soffits and columns, where the repair mortar can be hand-applied without specialist equipment: £70–110 per square metre of repair area, including breaking out to sound concrete, rust treatment of exposed steel, application of bonding agent and polymer-modified cementitious repair mortar, and finishing to match surrounding surface profile. For deeper spalling with section loss exceeding 40 mm, where shuttered or poured concrete reinstatement is required rather than hand-applied mortar: £120–200 per square metre, reflecting the higher material volume, the formwork costs and the longer curing time required before the works area can be released. For widespread carbonation repairs on large facades or multi-storey car park decks requiring full soffit repairs over extensive areas, economies of scale typically reduce the per-square-metre cost to £55–80 per square metre on quantities exceeding 200 square metres, because mobilisation and access costs are shared over a larger repair area.

Access is frequently the largest single cost item on spalling repair projects, particularly on multi-storey car parks, bridge soffits and buildings where conventional scaffold is impractical or economically disproportionate. Mobile elevated work platforms (MEWPs) are typically costed at £200–400 per day for medium-range platforms and £600–900 per day for tall or specialist platforms, with MEWP costs often representing 20–40% of the total project cost on access-critical structures. Rope access — used on tall structures where MEWP access is impractical and scaffold erection would be prohibitively expensive — is typically charged at a day rate for a two-person abseiling team of £800–1,400 per day, plus mobilisation and method statement preparation costs. The choice of access method should be made in conjunction with the repair contractor, not imposed unilaterally by the client or main contractor.

Carbonation-Induced Spalling vs Chloride-Induced Spalling: Does It Affect Cost?

The two dominant causes of cover concrete spalling on UK commercial structures are carbonation of the concrete matrix and chloride-induced corrosion of the reinforcement, and while both produce similar visual symptoms — map cracking, rust staining, delamination and eventual loss of cover concrete — they have different spatial distributions, different rates of progression and somewhat different implications for the repair specification and cost.

Carbonation-induced spalling occurs when atmospheric carbon dioxide reacts with the calcium hydroxide in the cement paste, neutralising the alkaline environment that protects reinforcement from corrosion. Carbonation proceeds as a front from the exposed surface inward at a rate governed by concrete permeability, cement content and exposure conditions. On poorly-specified concrete from the 1950s to 1980s — low cement content, high water-cement ratio, inadequate cover to reinforcement — carbonation fronts of 30–60 mm are not uncommon on UK facades and car park structures. The repair approach for carbonation-induced spalling — full break-out to carbonated concrete depth, rust treatment, re-alkalisation if specified, repair mortar reinstatement and anti-carbonation coating — is well-established and can be reliably costed on the basis of survey data.

Chloride-induced spalling is the dominant deterioration mechanism in marine-exposed concrete, in car parks where de-icing salt is tracked in on vehicle tyres, and in coastal structures. Its repair is more complex and typically more expensive than carbonation repair because chlorides diffuse into the concrete matrix and cannot be fully removed by conventional repair techniques. The repair specification must therefore address both the physical reinstatement and the protection of adjacent steel that remains at risk of chloride-induced corrosion. Impressed current cathodic protection (ICCP) or sacrificial anode cathodic protection (SACP) systems are increasingly specified alongside physical repair on chloride-contaminated structures to prevent further corrosion of reinforcement adjacent to the repair area — a process known as incipient anode formation. SACP system installation typically adds £40–80 per square metre to the repair cost but significantly extends the service life of the repair.

Repair Mortar Specification and Why It Matters for Cost

The choice of repair mortar system has a significant influence on both the immediate repair cost and the long-term performance and service life of the repair. BS EN 1504-3 (Products and Systems for the Protection and Repair of Concrete Structures — Structural and Non-Structural Repair) classifies repair mortars into four classes (R1–R4) based on their compressive strength and other mechanical properties, and a repair mortar should be selected that is appropriate to the structural significance of the repaired element and the exposure conditions it will face.

Pre-bagged polymer-modified cementitious repair mortars (R2–R3 classification) are the workhorses of the UK commercial repair market. Applied in layers of 10–50 mm, they offer good adhesion to prepared concrete substrates, low shrinkage, adequate strength and compatibility with anti-carbonation topcoat systems. Their material cost is typically £2–5 per kilogram, and on a volume basis, a 40 mm deep repair requires approximately 70–80 kg of mortar per square metre, putting material cost at £140–400 per square metre before labour, access and overhead. R4 (structural) repair mortars — higher strength, lower permeability, tested to BS EN 1504-3 for structural applications — are required for repairs to primary structural elements (columns, beams, transfer slabs) and carry a material cost premium of 20–40% over equivalent R2–R3 products.

Sprayed concrete (shotcrete) is used for large-volume repairs where hand-applied mortar would be impractical and where the geometry of the structure allows a continuous spray application. Wet-process shotcrete is specified for high-volume applications and delivers a dense, low-permeability repair material at production rates significantly higher than hand-applied mortar. The capital and plant costs associated with shotcrete application mean it is generally only cost-effective on areas exceeding 50 square metres; on smaller areas, hand-applied mortar remains the more economical choice. MPS Concrete Solutions carries out both hand-applied and spray-applied repair programmes and can advise on the most appropriate method for your specific structure and repair extent. Contact our team for a no-obligation survey and quotation, or review our guide to diagnosing concrete defects for further information on the survey techniques that inform a robust repair specification.