MC-Bauchemie MC-Nafufill N
A normal-setting, one-component polymer-modified repair mortar that gives your team the working time to patch concrete defects properly, not just quickly.
What is it?
A factory-blended, single-component cementitious repair mortar modified with redispersible polymers, supplied as a dry powder that you mix with clean water on site.
Where is it used?
General patch repair of concrete and masonry: tie-bolt holes, honeycombing, spalls, impact damage, culverts, balconies, facades and precast defects.
Why use it?
Its normal (unhurried) set gives roughly 3-4 hours of working time at 25C, so crews can place, compact and finish a neat repair without fighting a flash set.
How is it applied?
Hand-applied by trowel in lifts of 10-50 mm onto a saturated-surface-dry, mechanically prepared substrate, then kept moist-cured for 24-48 hours.
About MC-Bauchemie MC-Nafufill N
MC-Nafufill N belongs to MC-Bauchemie’s Nafufill family of concrete-repair mortars and sits at the everyday, general-purpose end of that range. It is a one-component, polymer-modified cementitious (PCC-type) mortar built around Portland cement, graded silica aggregate, redispersible polymer powders and mineral fillers. Everything is pre-batched at the factory, so the mix a contractor gets in Ghaziabad is the same as the one on a site in Chennai. On site the crew simply adds a measured quantity of clean water, mixes to a cohesive trowelable consistency, and applies. The “N” designation points to its defining trait: a normal, unhurried set of roughly 3-4 hours at 25C, which is exactly what you want for careful, quality-led repairs rather than emergency work.
That deliberate pace is what makes it a natural fit for volume maintenance and reprofiling. Site engineers reach for it when there are dozens of tie-bolt holes to fill after formwork strips, when honeycombed pours need making good, or when spalled edges on balconies, parapets and precast units have to be rebuilt before coating. Because it bonds to concrete, masonry, blockwork, render and stone, one product covers a lot of the small-to-medium remedial work that otherwise needs three or four SKUs. It is not marketed as a high-strength structural reinstatement mortar, and that honesty is the point: for its class it is a dependable, cost-sensible workhorse for the general repair scope that fills most contractors’ punch lists.
The technical insight
The performance comes from the redispersible polymer powders dispersed through the cement matrix. As the mortar cures, these polymers coalesce into a continuous film that bridges the cement hydration products, doing two useful things at once. First, the polymer film improves wetting and mechanical keying at the old-concrete interface, which is why bond strength lands around 0.8-1.0 MPa to EN 1542 rather than the weaker grip of a plain sand-cement patch that tends to debond as it dries. Second, the polymer reduces the effective water demand and restrains capillary movement, cutting the drying shrinkage that causes hairline map-cracking and edge lifting in unmodified mortars. The graded silica aggregate is sized so the mortar stays cohesive and non-slumping in lifts up to 50 mm yet still trowels to a closed, dense finish. The normal set chemistry keeps early hydration gentle, so the placed mortar does not skin over or stiffen before it has been fully compacted and struck off. Net result: a repair that stays put, keeps water and chloride out at the joint line, and behaves close enough to the parent concrete to serve as a sound base for protective coatings.
Where it is used
- Filling tie-bolt (form-tie) holes and cone holes after formwork removal
- Making good honeycombing, blowholes and grout loss on fresh structural pours
- Patch repair of spalled or impact-damaged concrete edges, corners and slabs
- Reprofiling balconies, parapets, chajjas and external facade elements before coating
- Repair of masonry, blockwork and rendered surfaces where a polymer-modified mortar is preferred
- Reinstating defects on precast concrete units, copings and architectural elements
- Making good culverts, drains and minor water-retaining/drainage structures
- General building-maintenance patching across residential, commercial and institutional stock
Key advantages
- Normal 3-4 hour set at 25C gives crews genuine working time for a neat, well-compacted repair
- One-component, just-add-water powder removes on-site batching guesswork and gauging errors
- Polymer modification raises bond strength (0.8-1.0 MPa, EN 1542) and cuts shrinkage cracking
- Builds 10-50 mm per lift, so most patches are a single application without formwork
- Broad substrate compatibility across concrete, masonry, blockwork, render and stone
- Factory-blended for batch-to-batch consistency and predictable finished appearance
- Cost-effective for high-volume general maintenance where premium structural mortar is overkill
- Trowel-friendly, cohesive mix that holds on vertical faces and finishes to a dense surface
Limitations & considerations
- Not a high-strength structural reinstatement mortar; 28-day compressive strength is around 20-25 MPa, so it suits general repair, not load-critical sections
- Maximum build is 50 mm per lift; deeper or larger-volume repairs need building up in layers or a heavier microconcrete
- The normal set is a drawback for emergency work; leak-stopping or rapid-return jobs need a quick-set product instead
- Cementitious and porous by nature, so it is a repair mortar, not a standalone waterproofing or protective layer
- Curing is unforgiving in Indian summer; without proper moist-curing and sun/wind protection, plastic shrinkage cracking is a real risk
- Bond depends entirely on substrate prep; over-watering the mix or skipping saturated-surface-dry conditioning will compromise the repair
Selection & best practice
Start with the substrate, not the mortar. Break out all loose, drummy or carbonated concrete back to a sound base, expose and clean any corroded steel, and prime reinforcement with an appropriate MC anti-corrosion primer where cover is compromised. Saw-cut or square-up the repair edges to avoid feather-edging, which always cracks. Pre-soak the prepared area to a saturated-surface-dry (damp but no standing water) condition before you place mortar. Add powder to a pre-measured quantity of clean water and mix with a paddle drill at 400-600 RPM for about 3 minutes to a uniform trowelable consistency; resist the urge to add extra water, as over-watering directly weakens strength and bond. Apply firmly in lifts of 10-50 mm, compacting well into the substrate and around any exposed steel, and finish before initial set. Consumption runs roughly 1.6-1.8 kg per square metre per millimetre of depth, which is what you use for take-off. Then protect the repair: keep it moist-cured for a minimum of 24-48 hours and shield it from direct sun and drying wind, especially in peak summer, to prevent plastic shrinkage cracking.
Specifications
| Product type | One-component polymer-modified cementitious repair mortar (PCC) |
| Composition | Portland cement, graded silica aggregate, redispersible polymer powder, mineral fillers |
| Initial set at 25C | Approx. 3 to 4 hours |
| Compressive strength (28 days) | Approx. 20 to 25 MPa |
| Adhesion to substrate (EN 1542) | Approx. 0.8 to 1.0 MPa |
| Application thickness | 10 to 50 mm per coat |
| Consumption | Approx. 1.6 to 1.8 kg per square metre per mm depth |
| Mixing | Paddle drill at 400 to 600 RPM for 3 minutes; do not over-water |
| Curing | Keep moist for minimum 24 to 48 hours; protect from sun and wind |
Industry use cases
Real estate & housing
Making good tie-holes, honeycombing and spalled edges across new residential towers before handover and coating.
Facade & repair contractors
Reprofiling balconies, parapets and facade elements during building rehabilitation where a neat, coatable patch is needed.
Precast & manufacturing
Reinstating cast defects, chipped corners and blowholes on precast units and architectural components in the yard.
Infrastructure & municipal
General repair of culverts, drains and minor concrete structures during routine civic maintenance programmes.
Facilities & maintenance
Ongoing patch repair of concrete and masonry across institutional, commercial and industrial building stock.
Frequently asked questions
Is MC-Nafufill N a structural repair mortar?
How thick can I apply it in one pass?
How much material do I need?
Why does it set slower than some other repair mortars?
What surface preparation does it need?
Does it waterproof the concrete?
How we position MC-Bauchemie MC-Nafufill N
MC-Nafufill N is the general-purpose workhorse of MC-Bauchemie’s Nafufill repair range for Space Arc customers. When the job needs more muscle, step up within the same family to the Nafufill KM series (such as Nafufill KM 250), a fibre-reinforced structural PCC microconcrete for load-bearing reinstatement, and pair repairs with an MC reinforcement primer plus an MC-Bauchemie protective anti-carbonation coating to seal the finished work. Because Space Arc is also an authorised Fosroc distributor and applicator, engineers who prefer the Fosroc system can specify the equivalent Renderoc range, and for rapid or emergency scopes, where MC-Nafufill N’s normal set is a poor fit, our Fosroc Renderoc Plug handles active water leaks. Match the mortar to the duty: MC-Nafufill N for volume general repair, KM-series or Renderoc HB for structural, Renderoc Plug for leak-stopping.
Fosroc Renderoc HB — A specifier may choose Renderoc HB when the repair is on vertical or overhead faces, needs an EN 1504-3 Class R2 classification, or must build thicker (up to 80 mm) in a single application without formwork.