MC-Bauchemie MC-Nafuplan HC
A fast-set hydraulic plugging cement that arrests running water leaks in minutes, straight against pressure, so crews can regain control of a wet joint or crack before permanent waterproofing goes on.
What is it?
A single-component, rapid-hardening hydraulic cement plugging compound from MC-Bauchemie, hand-mixed on site to seal live water leaks in concrete and masonry.
Where is it used?
Basement walls, lift pits, retaining walls, construction joints, service penetrations, tunnels and water tanks where pressurised seepage is running actively.
Why use it?
It sets in one to five minutes and hardens against flowing water, letting a crew plug a leak on the spot without waiting for the source to be shut off.
How is it applied?
Mixed by hand to a stiff putty, shaped into a plug, pressed firmly into the leaking point and held for three to five minutes until it takes its initial set.
About MC-Bauchemie MC-Nafuplan HC
MC-Nafuplan HC is the product a site team reaches for the moment water starts jetting out of a crack, cold joint or pipe penetration and the pour has to keep moving. It is a dry, factory-blended hydraulic cement that needs only clean water on site. Once gauged to a stiff, dough-like consistency it develops strength almost immediately, which is what allows it to be forced into a leak that is still under head and to stay put rather than wash away. For engineers and contractors working basements, lift pits and water-retaining structures across Delhi NCR and the rest of India, it turns an emergency into a ten-minute repair rather than a shutdown.
The compound belongs to MC-Bauchemie’s speciality repair and waterproofing family, the German construction-chemicals house that has manufactured in India since the late 1980s. It is best understood as a first-response tool, not a finished waterproofing system: it stops the flow and buys the crew a dry surface to work on. Space Arc Engineering supplies it as an authorised distributor and, where required, applies it as part of a full basement or below-ground remediation package, pairing the plug with the surface coatings and injection grouts that actually deliver the long-term seal.
The technical insight
The speed comes from chemistry rather than any accelerating admixture the applicator has to add. The cement is formulated rich in the reactive aluminate phase, so when it meets water it forms ettringite crystals very quickly. Those needle-like crystals grow into and interlock across the mix within the first couple of minutes, which is why the material stiffens in the hand and reaches a low but real strength almost at once. Crucially, the reaction is not disrupted by the water it is being pressed against, so the plug keeps building strength even while a leak is still trying to push through it. A mild expansion as it sets helps the plug key tightly into the sides of the crack or hole, so it seals against the substrate instead of simply blocking the opening. That is a different mechanism from an ordinary repair mortar, which needs a dry, quiet substrate and hours of cure before it can resist any head at all.
Where it is used
- Stopping high-pressure water jets in basement and retaining walls where seepage is already running
- Sealing leaking construction joints and cold joints during and after a pour
- Plugging around pipe sleeves, conduits and other service penetrations that are weeping
- Arresting leaks in lift pits, sumps, water tanks and other water-retaining structures
- Emergency water stops in tunnels, shafts, access chambers and below-ground utilities
- Filling and sealing tie-rod holes and formwork blowouts that are letting water through
- Fixing anchors or fittings rapidly where a fast grab in wet conditions is needed
- Creating a dry working surface ahead of applying a permanent waterproofing coating
Key advantages
- Sets in roughly one to five minutes, so a crew can plug a live leak without shutting off the source
- Hardens against flowing water and pressure rather than needing a dry substrate first
- Single component that only needs clean water, mixed by hand with no special plant
- Slight controlled expansion keys the plug into the leak and seals against the surrounding concrete
- Gains useful strength within minutes and continues to build over the first day
- Chloride-free and cement-based, so it will not corrode embedded reinforcement
- Simple enough for a general site team to use in an emergency with minimal training
- Backed by MC-Bauchemie manufacturing and Space Arc’s local supply and application support
Limitations & considerations
- It is a leak-stopping compound, not a standalone waterproofing system, so the surface still needs a proper coating or injection afterwards
- The very short working time means only small batches can be mixed, and the crew must be ready before gauging water is added
- Setting speed drops in cold conditions and accelerates in heat, so pot life shifts with ambient temperature
- It seals discrete leaks, cracks and holes; it is not a substitute for treating large seeping areas or structural cracks
- Best results depend on cutting or chasing the leak to a sound, keyed opening before plugging, which takes site judgement
- Shelf life is limited and the powder must be kept dry and sealed, as absorbed moisture kills the reactivity
Selection & best practice
Prepare before you mix, because there is no time to improvise once water hits the powder. Where practical, cut or chase the leaking crack or hole into an undercut or dovetail shape so the plug has something to key into rather than a shallow ledge that water can push out. Remove loose material and any laitance. Gauge only as much powder as one person can place in a minute or so, add clean water to a stiff, mouldable putty, and work it in gloved hands until it just begins to warm and stiffen. Press it firmly into the leak point and hold with steady hand pressure for three to five minutes until it has clearly taken its set; do not keep reworking it once it starts to go off. Start at the top of a leaking area and work down, and against a strong jet, plug the sides first to concentrate the flow before sealing the centre. Once the surface is dry and stable, follow up with a permanent MC-Bauchemie waterproofing coating such as the Zentrifix or Dichtament cementitious systems, or a resin injection where the leak runs deep, so the plug becomes part of a lasting seal rather than a temporary fix.
Specifications
| Product type | Single-component rapid-hardening hydraulic plugging cement |
| Base chemistry | High-aluminate hydraulic cement (rapid ettringite formation) |
| Mixing | Powder gauged with clean water on site to a stiff putty |
| Initial set (typical, ~25 C) | Approx. 1 to 5 minutes from mixing |
| Early strength (indicative) | ~2 to 5 MPa within about 15 minutes |
| Later strength (indicative) | ~20 to 30 MPa at 24 hours |
| Colour / form | Grey cementitious powder |
| Application temperature | Suited to normal site conditions up to about +35 C |
| Function | Emergency leak stop and preparation for permanent waterproofing |
Industry use cases
Commercial & residential basements
Arresting seepage jets in basement and retaining walls during construction, then handing over to a coating system for the permanent below-ground seal.
Water & wastewater structures
Plugging leaks in tanks, sumps, treatment structures and access chambers where water is standing or running while repairs proceed.
Infrastructure & tunnels
Emergency water stops in tunnel linings, shafts and utility ducts, where a fast grab against inflow keeps work fronts open.
Industrial & plant maintenance
Sealing weeping pipe penetrations, pits and joints in operating facilities where a full shutdown to dry the area is not practical.
Repair & remediation contractors
A go-to first-response product in the waterproofing kit, used to stabilise a wet substrate before injection grouting or coating.
Frequently asked questions
Does MC-Nafuplan HC stop water that is actively leaking under pressure?
Is this a complete waterproofing solution on its own?
How long do I have to work with it after mixing?
Will it corrode the steel reinforcement in the concrete?
How is it different from a normal repair mortar?
Can Space Arc supply and apply it across India?
How we position MC-Bauchemie MC-Nafuplan HC
MC-Nafuplan HC is a first-response leak stopper, so it works best when specified alongside the products that finish the job. Within the MC-Bauchemie family, pair it with the cementitious waterproofing coatings in the Zentrifix and Dichtament ranges for the permanent seal once the surface is dry, and with an MC injection resin or grout where a leak runs deep into a crack rather than sitting at the face. Across our other brands, Space Arc also stocks directly equivalent rapid plugging cements and complementary crystalline and membrane waterproofing systems from Fosroc, Sika and Dr. Fixit, so consultants can match the plug to whatever waterproofing spec the rest of the structure already follows.
Fosroc Renderoc Plug — Choose the Fosroc option when the project is already specified around Fosroc’s waterproofing system or when you want a defined grade choice — Renderoc Plug 1 for a roughly one-minute set or Renderoc Plug 20 for more working time.
Related Waterproofing products
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.