MC-Bauchemie MC-RocTec 222 F
A fine-textured, polymer-modified R4 repair mortar built for hand-application on edges, corners, soffits and fair-faced concrete where a smooth, structural finish matters.
What is it?
A single-component, cement-based, polymer-modified repair mortar with a fine aggregate (max 1 mm), classified EN 1504-3 Class R4 for structural concrete reinstatement.
Where is it used?
Column edges and corners, beam soffits, slab edges and cantilevers, bridge parapets, and architectural or heritage concrete where the repair stays visible.
Why use it?
Delivers R4-grade strength (>45 MPa at 28 days) with a fine, workable texture that trowels down to a clean, closed surface without honeycombing on detailed profiles.
How is it applied?
Site-mixed with 0.12-0.15 litres of clean water per kg of powder, then hand-applied by float, trowel or screed in 5-40 mm layers over a primed, saturated substrate.
About MC-Bauchemie MC-RocTec 222 F
MC-RocTec 222 F sits in the fine end of MC-Bauchemie’s structural repair range. Where high-build mortars are formulated to hang thick on vertical and overhead faces, this one is engineered around a maximum 1 mm aggregate so it can be worked into edges, arrises and shallow reinstatements and still be closed off to a genuinely smooth face. That makes it the mortar a site team reaches for when the repair will remain exposed – a spalled column corner in a lobby, a chipped beam soffit under a canopy, or a heritage element where the patch must disappear into the surrounding concrete.
Despite the fine texture, it is a full structural product. It carries EN 1504-3 Class R4 classification, the highest strength band in the concrete-repair standard, with 28-day compressive strength above 45 MPa and pull-off bond above 2.0 MPa on a properly prepared substrate. For engineers and consultants specifying a repair on a load-bearing element, that combination – fine finish plus R4 mechanicals – is the reason to choose 222 F over a general-purpose patching compound. It is supplied as a pre-blended dry powder, so the only site variable is water, which keeps batch-to-batch consistency tight across a large repair programme.
The technical insight
The performance comes from two things working together: a polymer-modified cement matrix and a tightly graded fine aggregate. The polymer content raises adhesion and lowers the water demand, so the mortar bonds intimately to the parent concrete and cures with fewer shrinkage micro-cracks at the interface – the zone where most repairs eventually fail. The fine aggregate, capped around 1 mm, is what lets the material be feathered and closed at edges and thin sections; a coarser mortar simply cannot be tooled to the same smooth, dense skin on a detailed profile. Because it is graded for 5-40 mm per layer, each pass carries enough body to resist slump on a vertical face yet stays thin enough to follow the original geometry. The result is a repair that behaves monolithically with the substrate: matched enough in stiffness and thermal movement to act as one, strong enough to take structural load, and dense enough to re-establish cover protection over cleaned reinforcement.
Where it is used
- Rebuilding spalled or damaged column edges, corners and arrises
- Reinstating beam soffits and undersides where cover concrete has failed
- Repairing slab edges, drip channels and cantilever noses
- Bridge parapet, barrier and kerb reinstatement
- Architectural and fair-faced concrete patching where the repair stays visible
- Heritage and conservation concrete restoration requiring a fine finish
- Shallow structural reinstatement over cleaned, primed reinforcement
- Making good after chipping-out and corrosion treatment of embedded steel
Key advantages
- EN 1504-3 Class R4 – top strength band, suitable for load-bearing repairs
- Fine 1 mm aggregate tools down to a smooth, closed, fair-faced finish
- High compressive strength (>45 MPa at 28 days) with >2.0 MPa bond
- Single-component powder – only clean water added on site, so batches stay consistent
- Builds 5-40 mm per layer, handling both edges and moderate depth
- Polymer modification improves adhesion and reduces interface shrinkage cracking
- Hand-applied by trowel, float or screed – no specialist plant for most repairs
- Re-establishes cover and alkaline protection over cleaned reinforcement
Limitations & considerations
- Layer thickness is capped at 40 mm per pass; deeper voids need building up in lifts or formwork support beyond ~30 mm overhangs
- Not suited to high-volume, deep-section pours where a flowable microconcrete is more economical
- Application window is 5 C to 35 C – hot Indian afternoons need water-ratio adjustment and shading
- Requires correct surface prep, rebar cleaning to Sa 2 / St 3 and a corrosion-inhibitor primer to perform as rated
- Fine texture is a finishing advantage, not a substitute for the coarser body needed in very thick reinstatements
- Needs disciplined wet curing (3 days minimum, 7 preferred) or shrinkage and low strength can follow
Selection & best practice
Break out all deteriorated concrete with a rotary breaker or hammer drill, cutting the perimeter square or slightly undercut – never feather-edged – to a minimum sound depth. Expose and clean corroded reinforcement back to bright steel (Sa 2 / St 3 equivalent), then apply the specified corrosion-inhibitor primer and let it take. Pre-saturate the substrate to a saturated-surface-dry condition so the mortar is not robbed of mixing water. Mix with 0.12-0.15 litres of potable water per kg of powder using a slow-speed drill (400-600 rpm) until uniform and lump-free; adjust to the lower end of the water range in hot weather. Apply firmly by hand in 5-40 mm layers, working the first pass hard into the primed surface to eliminate voids, and support overhangs deeper than about 30 mm with formwork. Close the surface with a float or trowel, then cure under wet hessian and polythene for at least 3 days, ideally 7 – this single step protects both strength and finish.
Specifications
| Type | Single-component, polymer-modified cementitious repair mortar |
| EN 1504-3 Class | R4 (structural) |
| Maximum aggregate size | 1 mm (fine) |
| Compressive strength | >45 MPa at 28 days |
| Bond strength | >2.0 MPa (pull-off on prepared concrete) |
| Layer thickness | 5 mm min to 40 mm max per layer |
| Water demand | 0.12-0.15 litres per kg of powder |
| Application temperature | 5 C to 35 C |
| Curing | Wet hessian + polythene, 3 days minimum (7 preferred) |
Industry use cases
Bridges & Infrastructure
Reinstating parapet edges, kerbs and cantilever noses on road and rail structures where the repair remains exposed to traffic, weather and public view.
Commercial & Institutional Buildings
Restoring spalled column corners and beam soffits in lobbies, atria and covered walkways where a smooth, paint-ready fair-faced finish is expected.
Heritage & Conservation
Fine-textured patching of ornamental and historic concrete where the repair must blend invisibly into the original surface.
Car Parks & Podiums
Making good spalled edges and slab noses over cleaned, primed reinforcement to restore both cover protection and structural section.
Industrial & Water Structures
Localised R4 repairs to edges and shallow sections on tanks, channels and plant structures needing durable, dense reinstatement.
Frequently asked questions
What EN 1504-3 class is MC-RocTec 222 F?
How is it different from a high-build repair mortar?
What is the maximum repair depth in one application?
How much water do I add?
Do I need to treat the reinforcement first?
Can it be applied in Indian summer conditions?
How we position MC-Bauchemie MC-RocTec 222 F
MC-RocTec 222 F is the fine-finish member of a repair system, not a standalone product. Pair it with an MC-Bauchemie zinc-rich or cementitious rebar primer and a fairing coat from the same family so the specification stays single-source and warranty-clean. Where the same job also has deep, honeycombed or heavily reinforced sections that 222 F’s 40 mm limit cannot economically fill, step up to a flowable microconcrete for those pours and keep 222 F for the edges and exposed faces. Across our other brands, engineers who prefer a Fosroc-specified system can substitute the Renderoc range for equivalent R4 hand-applied work; for large horizontal wearing repairs, a Fosroc or Sika free-flow micro-concrete is the better tool. Space Arc supplies and applies all of these across Delhi NCR and Pan-India, so the mortar, primer and finishing coat can be sourced as one coordinated package.
Fosroc Renderoc HB40 — Specify the Fosroc option when the project is already standardised on a Renderoc system or when the repair leans toward high-build vertical and overhead reinstatement rather than fine-finish edge work.
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