MC-Bauchemie MC-Nafuplan
A single-component crystalline coating that grows insoluble crystals inside concrete to seal capillaries and hairline cracks, holding water from either face.
What is it?
A single-component, cement-based crystalline waterproofing coating from MC-Bauchemie, supplied as a factory-premixed powder that is gauged with clean water on site.
Where is it used?
Water-retaining and below-grade concrete: basement rafts and retaining walls, water tanks and reservoirs, tunnels, lift pits, sumps, swimming pools and underground car parks.
Why use it?
It waterproofs the concrete itself rather than sitting on top as a film, so it resists both positive and negative water pressure and keeps self-sealing minor cracks over time.
How is it applied?
Brush or spray two to three coats onto a saturated-surface-dry substrate at roughly 1.5-2.0 kg/m2 total, then damp-cure for at least three days.
About MC-Bauchemie MC-Nafuplan
MC-Nafuplan is MC-Bauchemie’s answer to a problem every basement and water-tank contractor knows well: membranes and paint-on coatings fail wherever they are punctured, poorly lapped or debonded, and once water finds a path behind them the whole system is compromised. Instead of forming a skin over the slab, MC-Nafuplan turns the outer few centimetres of the concrete into the waterproofing barrier. The powder is gauged with clean water and applied by brush or spray, and its active crystalline compounds are carried into the concrete by the moisture already present in the pores. There they react and stay, which is why the treated concrete continues to resist water even if the visible surface is later scuffed, plastered over or tiled.
For a distributor-applicator working across Delhi NCR and Pan-India, that behaviour matters most on the jobs where you cannot get to the outside face. A basement retaining wall cast against shoring, an existing tank that is leaking from within, a lift pit surrounded by soil, these are all situations where you must stop water pushing in from behind, and MC-Nafuplan is built to be applied on that inner, negative face and still hold. It is a two-part conversation with the substrate rather than a single-shot film, so the emphasis in specification and on site is on sound, clean, saturated concrete and honest curing, not on chasing a perfect pinhole-free coat.
The technical insight
The mechanism is diffusion-driven crystallisation. Cured concrete is never fully hydrated; it retains unreacted cement grains, free lime and a network of capillary pores and microcracks that water uses as pathways. When MC-Nafuplan is applied to a saturated surface, its soluble crystalline actives dissolve in the pore water and migrate inward by osmosis and capillary action. As they meet moisture, free lime and the unhydrated cement, they react to precipitate insoluble calcium silicate hydrate crystals directly inside the pores and along fine cracks. These needle-like crystals grow to fill the voids, so the concrete’s permeability drops sharply while the matrix stays vapour-open and is not merely coated. Because the actives remain dormant until water is present, later ingress reactivates them and drives fresh crystal growth into any new hairline crack up to about 0.4 mm, giving the concrete a genuine self-healing character. This is also why the treatment resists negative-side pressure: the barrier is monolithic with the concrete, not a film that water can lift off.
Where it is used
- Negative-side and positive-side waterproofing of basement rafts, retaining walls and podium slabs
- Internal lining of potable water tanks, reservoirs and clear-water sumps
- Sewage and effluent treatment structures, wet wells and channels
- Tunnels, subways, cut-and-cover boxes and underground metro works
- Lift pits, machine pits and drainage sumps where the outer face is inaccessible
- Swimming pools, water features and balancing tanks
- Foundations and pile caps in high water-table ground
- Sealing of construction joints, honeycombing and static hairline cracks in combination with the appropriate detailing
Key advantages
- Waterproofs within the concrete, so performance survives surface abrasion, plastering and tiling
- Resists both positive and negative hydrostatic pressure, making it viable on inaccessible outer faces
- Self-seals fresh hairline cracks up to about 0.4 mm as water reactivates the crystals
- Single-component powder, gauged only with clean water, so there is no mix-ratio guesswork with resins
- Vapour-permeable, letting the structure breathe rather than trapping moisture behind a film
- Non-toxic once fully cured and suitable for potable-water storage
- Bonds to and becomes integral with the substrate, with no separate primer or membrane to lap or puncture
- Straightforward brush or spray application that a trained site crew can execute at scale
Limitations & considerations
- It waterproofs concrete, not renders, blockwork or plaster, so it must be applied to a sound structural concrete substrate
- It seals hairline, non-structural cracks only; moving, structural or wide cracks need routing, filling or a joint-treatment system first
- Substrate preparation is demanding: the surface must be clean, open-textured and genuinely saturated-surface-dry for crystals to migrate
- It is rigid and non-elastomeric, so it will not bridge live joints or accommodate ongoing movement
- Curing discipline is critical; without several days of damp curing the crystalline reaction is starved and performance drops
- Full cure is needed before a potable tank is put into service, so it is not an instant-return solution
Selection & best practice
Start with the concrete, not the coating. Remove laitance, curing compounds, form oil and any loose material by water-jetting or light scabbling until you expose an open, slightly rough capillary structure for the crystals to enter. Pre-soak thoroughly and bring the surface to a saturated-surface-dry condition, damp to the touch with no standing water, since that pore moisture is what carries the actives inward. Mix only clean water into the powder at roughly 3.5-4.0 litres per 25 kg bag to a lump-free, brushable slurry, and use it within its working time rather than re-tempering. Apply two to three coats to build about 1.5-2.0 kg/m2 in total, taking the second coat while the first is still green so they knit together, and treat construction joints, wall-floor junctions and honeycombed patches as separate detailing tasks. The single most important step is curing: keep the coating damp by fog spray or wet hessian for at least three days, and allow the recommended time before any surface covering or, for water tanks, before filling and commissioning.
Specifications
| Product type | Single-component cementitious crystalline waterproofing coating |
| Form | Factory-premixed grey powder, gauged with clean water on site |
| Total application rate | Approx. 1.5-2.0 kg/m2 over 2-3 coats |
| Mixing ratio | Approx. 3.5-4.0 litres clean water per 25 kg bag |
| Application method | Brush or spray onto saturated-surface-dry (SSD) concrete |
| Crack self-sealing | Hairline, non-structural cracks up to approx. 0.4 mm |
| Water pressure resistance | Resists positive and negative hydrostatic pressure |
| Potable water contact | Non-toxic and suitable for drinking-water storage after full cure |
| Curing | Minimum 3 days damp curing; allow 7 days before surface covering |
Industry use cases
Residential and commercial basements
Applied to the inner face of retaining walls and rafts cast against shoring, where the outside is buried and only negative-side treatment is possible.
Water utilities and plumbing
Lines potable water tanks, reservoirs and sumps, curing to a non-toxic barrier before the structure is filled and commissioned.
Infrastructure and tunnelling
Waterproofs tunnels, subways and cut-and-cover boxes against ground-water head from either face without a separate sheet membrane.
Water and effluent treatment
Protects wet wells, channels and treatment tanks where continuous saturation would defeat a surface film but suits crystalline growth.
Deep pits and services
Seals lift pits, machine pits and drainage sumps from the inside, holding back the surrounding water table where excavation access is gone.
Frequently asked questions
Can MC-Nafuplan be applied from the inside if I can’t reach the outer face?
Is it safe for drinking-water tanks?
Will it seal cracks in my concrete?
How is it different from a brush-applied cementitious membrane like Brushbond RFX?
What coverage and pack size should I plan for?
How much surface preparation does it really need?
How we position MC-Bauchemie MC-Nafuplan
MC-Nafuplan is the right call when the concrete itself must become the barrier, especially on negative-side and water-retaining work. Where the design instead needs a flexible, crack-bridging film on the surface, MC-Bauchemie’s own brush-applied cementitious coatings in the MC-Bauchemie waterproofing range are the better fit, and for below-grade tanking against soil a bituminous or sheet membrane system may be specified alongside it. Across our other brands we regularly pair or substitute this with Dr. Fixit and STP options for terrace and wet-area membranes, and with Sika crystalline and cementitious systems where a project standard calls for them. For crack routing and joint sealing that must precede any crystalline coat, we cross-sell the appropriate sealants and repair mortars from the same brand families so the whole detail is covered.
Fosroc Brushbond TGP — Choose the Fosroc option when the project or consultant standardises on Fosroc and wants a single-component crystalline tanking-grade powder with the same integral, both-faces waterproofing behaviour.
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