MC-Bauchemie MC-Nafuplan EW
A water-based, polymer-modified bitumen emulsion that brushes on as a seamless, crack-bridging waterproof membrane for roofs, terraces and podium decks.
What is it?
A single-component, SBR-modified bitumen emulsion from MC-Bauchemie that dries into a flexible, seamless waterproof film.
Where is it used?
Roof slabs, building terraces, podium decks, balconies, water-tank roofs and remedial re-waterproofing over failed systems.
Why use it?
It bridges hairline and moving cracks, is water-based and low-odour, and needs no torching or hot work to apply.
How is it applied?
Brush or roller in 2 to 3 coats over a clean, primed, sound substrate to build the specified dry film thickness.
About MC-Bauchemie MC-Nafuplan EW
MC-Nafuplan EW belongs to MC-Bauchemie’s Nafuplan family of bituminous waterproofing products, but unlike the torch-applied membranes in that range, EW is a cold-applied liquid. It arrives as a ready-to-use bitumen emulsion modified with synthetic rubber (SBR-type) polymer, which is what gives the cured film its stretch and its ability to move with the structure rather than crack alongside it. Because it is water-based, there is no solvent smell, no flame and no molten kettle on site, which makes it a practical choice for occupied buildings, water-retaining structures and confined terraces where hot work is awkward or unsafe.
For engineers and applicators, the appeal is straightforward. The product goes down by brush or roller, wets into the substrate, and knits coat-to-coat into one continuous skin with no laps, seams or welds to fail later. It suits both fresh construction and rehabilitation work, where an old, tired waterproofing system needs to be over-coated rather than fully stripped. Delhi NCR summers, monsoon standing water and the thermal cycling that terraces endure are exactly the conditions a flexible bituminous coating is built for, provided it is protected from direct, prolonged UV exposure with a screed, tile or reflective topcoat.
The technical insight
The waterproofing performance comes from two things working together: the bitumen and the polymer. Bitumen on its own is an excellent water barrier but is brittle when cold and soft when hot. Blending in a synthetic rubber (SBR-type) polymer changes that behaviour band. The rubber phase disperses through the bitumen and stays elastic across a much wider temperature range, so the dried film can stretch over a hairline crack that opens under thermal movement and then close again without tearing. As an emulsion, the coating carries the bitumen as fine droplets suspended in water; when applied, the water evaporates and the bitumen droplets coalesce into a dense, homogeneous film. This coalescence is why coverage rate and coat count are not negotiable numbers, they are what delivers the continuous dry film thickness that actually resists hydrostatic pressure. Too thin, and pinholes and weak zones remain; the specified 2 to 3 coats exist to guarantee an unbroken, adequately thick membrane.
Where it is used
- Waterproofing of RCC roof slabs and building terraces before screed or tiling
- Podium deck and balcony waterproofing under protective toppings
- External faces of water-tank roofs and non-potable water-retaining structures
- Remedial over-coating of aged or failed bituminous and coating systems
- Damp-proofing of foundation and plinth surfaces below grade
- Sunken slabs of toilets, bathrooms and utility areas ahead of backfill
- Chajjas, parapet junctions and gutters where a seamless liquid film suits the geometry
- Sandwich waterproofing between screed layers on flat roofs
Key advantages
- Seamless, liquid-applied film with no laps or welded joints to fail over time
- Bridges hairline and small moving cracks thanks to the rubber-modified elasticity
- Cold applied by brush or roller, so no flame, hot kettle or specialist torching crew
- Water-based and low-odour, suitable for occupied buildings and confined spaces
- Bonds well to sound concrete and masonry without an aggressive primer regime
- Follows complex geometry, upstands and penetrations easily as a liquid
- Works on both new construction and remedial re-waterproofing projects
- Fast enough turnaround that a two-to-three coat system can be built in a working day cycle in good weather
Limitations & considerations
- Not UV-stable, so exposed areas must be protected with a screed, tile, board or reflective topcoat
- Cannot be applied over standing water or during rain, and needs a dry weather window between coats
- Substrate moisture and surface condition matter; damp, laitance-covered or dusty surfaces compromise adhesion
- As a bituminous emulsion it is not intended for potable water contact or continuous chemical immersion
- Curing and film formation slow down markedly in cold, humid or poorly ventilated conditions
- Being cold-applied, it lacks the puncture resistance of a reinforced torch-on membrane on exposed high-traffic roofs unless well protected
Selection & best practice
Success is decided at the substrate. The surface must be structurally sound, free of laitance, loose material, oil and dust, with all sharp edges and honeycombing made good and coves formed at wall-floor junctions. Chase and fill active cracks; do not simply coat over them. Check that surface moisture is within the manufacturer’s limit before starting, and dampen very absorbent or a prime coat as recommended so the first coat wets in rather than skinning too fast. Apply in even, full coats by brush or roller, and always allow each coat to dry and develop film before the next, laying successive coats at right angles to eliminate pinholes. Do not exceed the recommended per-coat wet rate in a single pass, as an over-thick layer traps water and cracks on drying. Keep application within the 5 to 40 degree C ambient window, avoid work when rain is imminent, and cover the finished membrane with its protection layer promptly since the coating is not made to stay bare in sunlight. Reinforcing critical details such as corners, drains and upstands with a scrim within the coats adds durability where movement concentrates.
Specifications
| Product type | SBR/polymer-modified bitumen emulsion, cold liquid-applied |
| Base chemistry | Bitumen modified with synthetic rubber polymer, water-based |
| Application method | Brush or roller |
| Number of coats | 2 to 3 coats |
| Application temperature | 5 to 40 degree C ambient |
| UV stability | Not UV-stable; requires a protection layer |
| Pack size | 20-litre pails |
| Finish | Seamless, flexible black membrane |
Industry use cases
Residential
Waterproofing apartment roof slabs, terraces and balconies under screed or tile, and re-treating leaking older roofs without stripping the whole system.
Commercial
Terrace and podium-deck waterproofing on office and retail buildings where a cold, low-odour liquid can be applied without disrupting occupants below.
Water infrastructure
Coating the external roof faces of non-potable water tanks and sumps that need a flexible, seamless barrier.
Repair and rehabilitation
Over-coating failed bituminous or coating systems on ageing roofs and plinths as a cost-effective remedial waterproofing layer.
Below-grade
Damp-proofing foundation, plinth and retaining surfaces before backfilling, where the membrane stays protected by the surrounding fill.
Frequently asked questions
Is MC-Nafuplan EW a torch-applied membrane like other Nafuplan products?
Can it be left exposed on an open terrace?
How many coats are needed and why?
Will it bridge cracks in the slab?
Can I use it to fix an old roof that already leaks?
Is it safe for drinking-water tanks?
How we position MC-Bauchemie MC-Nafuplan EW
Within MC-Bauchemie’s own Nafuplan and Nafuflex waterproofing families, MC-Nafuplan EW is the cold-applied, brush-grade option; where a specifier needs a reinforced, high-build barrier for exposed or trafficked roofs they would step up to a torch-on Nafuplan membrane or a thick polymer-modified bituminous coating from the Nafuflex line. As a distributor and applicator across Delhi NCR and Pan-India, Space Arc also positions EW against cementitious flexible coatings such as Fosroc Brushbond RFX, which is the better call when the surface needs to breathe or will stay permanently exposed, and against acrylic and PU liquid membranes where UV exposure without a protection layer is unavoidable. For below-grade and podium work the honest comparison is a black flexible membrane like Fosroc Nitoproof 600.
Fosroc Nitoproof 600 — A specifier working below grade or on podium decks who wants a chemically cured, tougher black membrane may prefer Nitoproof 600, a pitch-modified polyurethane, over a water-based bitumen emulsion, accepting the higher cost and hot-appearance chemistry for greater robustness.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.