Fosroc Nitoproof 120
Single-component, fibre-reinforced bituminous liquid membrane for below-ground and concealed waterproofing — cold-applied by brush, roller or trowel.
What is it?
A single-component, cold-applied bituminous waterproof coating based on selected bitumens blended with non-asbestos reinforcing fibres, forming a high-build, flexible, jointless film.
Where is it used?
Below-ground structures, foundations, retaining walls, plinth beams, sandwich-construction floors and walls, water-tank linings and protected roof slabs — wherever the membrane stays concealed from sunlight.
Why use it?
It gives a continuous, fibre-reinforced barrier that resists water, water vapour and naturally occurring chemicals, with proven 30-year field performance and easy single-pack application at low cost.
How is it applied?
Prime the clean, dry substrate with Nitoproof 110, then apply two coats of Nitoproof 120 by brush, roller or trowel at roughly 2 to 2.5 m2 per litre per coat, allowing each coat to dry.
About Fosroc Nitoproof 120
Fosroc Nitoproof 120 is a single-component, fibre-reinforced bituminous waterproofing coating engineered for concealed and below-ground waterproofing. It is built on selected bitumens blended with non-asbestos reinforcing fibres, which give body to the dried film and act as in-built reinforcement. The result is an intermediate-thickness, high-film-build coating that dries to a tough yet flexible bituminous skin able to accommodate the minor thermal and structural movement that masonry and concrete experience in service.
For specifiers and site engineers in India, the appeal of Nitoproof 120 lies in its simplicity. It arrives ready to use in a single pack with no mixing ratios to control, no hot work, and no specialist equipment. The material is cold-applied by brush, roller or trowel directly onto a primed substrate, so it conforms easily to rough, contoured and irregular surfaces — retaining-wall faces, plinth beams, raft soffits and tank walls — and cures into a continuous, jointless film with no laps or seams to fail. Because it is asbestos-free, odourless and taint-free once dry, it can be used to line water-storage tanks where many older bituminous products could not.
Nitoproof 120 belongs to Fosroc’s long-established Nitoproof family of liquid-applied and membrane waterproofing systems. It is positioned as the workhorse bituminous protective coating for sandwich construction and external below-ground treatment — distinct from Fosroc’s elastomeric and polyurethane membranes (such as the Nitoproof 600/800/900 series and Brushbond ranges) that are chosen when UV exposure, heavy crack-bridging or exposed-roof duty is required. At Space Arc Engineering, an authorised Fosroc distributor and applicator serving Delhi NCR and Pan-India, Nitoproof 120 is most often specified for foundation tanking, basement protection and damp-proof membranes in sandwich floors and walls.
The technical insight
The defining feature of Nitoproof 120 is the non-asbestos fibre that is dispersed through the bitumen. In a plain bitumen coating, thermal cycling tends to draw the film thin over high points and pool it in hollows, eventually leading to crazing and cracking; the fibres knit the film together, hold a consistent build over edges and contours, and reinforce the coating against that movement. This is why the product is rated as an intermediate-thickness, high-build coating rather than a thin sealer. The cured film is also vapour-resistant, which matters for below-ground tanking and for the damp-proof membranes it forms inside sandwich construction. Standards compliance is genuine and worth quoting in specifications: the material meets ASTM D1227:1995 Type 2, Class 1, satisfies the ASTM C309 water-retention requirement when applied at 2.5 m2/litre, passes the BS 3416 flexibility test, and — used at the correct build — delivers a dry-film thickness consistent with BS 8102 for concrete protection and waterproofing. The trade-off is inherent to bitumen chemistry: the film is susceptible to ultraviolet light and must not be left permanently exposed to direct daylight, and it resists water, salt solutions and mild acids and alkalis but is not resistant to organic solvents.
Where it is used
- Tanking and external waterproofing of below-ground concrete and masonry against water ingress and aggressive ground
- Horizontal and vertical damp-proof membranes in sandwich-construction floors and walls
- Lining and waterproofing of water-storage tanks, including tanks intended for potable water
- Protective waterproof coating to foundations, raft soffits, plinth beams and retaining-wall faces
- Concealed waterproofing under screeds, protected roof slabs and podium decks not exposed to daylight
- Economy roof membrane for low-cost, non-critical roofing, with Nitoproof Scrim reinforcement over cracks
- Repairs and overcoating to existing felt or asphalt roof areas that will subsequently be covered
Key advantages
- Single-component and ready to use — no mixing, no fixed ratios, minimal wastage
- Cold-applied with no heating, naked flame or hazardous hot-work on site
- Fibre reinforcement resists crazing and cracking under thermal and structural movement
- Forms a continuous, jointless, high-build film with no laps or seams to fail
- Brush, roller, trowel or spray application conforms to rough and contoured surfaces
- Asbestos-free, odourless and taint-free when dry — suitable for potable-water tank linings
- Resistant to water, water vapour, salt solutions, detergents and mild mineral acids and alkalis
- Recognised standards compliance (ASTM D1227 Type 2 Class 1, ASTM C309, BS 8102, BS 3416)
- Long, proven track record across diverse below-ground and concealed environments
Limitations & considerations
- UV-sensitive — must not be left permanently exposed to direct daylight; needs covering or protection
- Not resistant to organic solvents; unsuitable where solvent or hydrocarbon exposure is expected
- Requires a clean, dry, oil- and grease-free substrate; will not bond over laitance, rust or mill scale
- Must be primed with Nitoproof 110 before application — it is not a stand-alone one-coat system
- Black bituminous finish only — no decorative or colour options
- Drying slows markedly in cold weather and at higher film thicknesses, extending the programme
- Best suited to concealed and below-ground use rather than trafficked or exposed-roof waterproofing
Selection & best practice
Always start with sound surface preparation: the substrate must be clean, sound and dry, with all laitance, dust, rust, mill scale and curing-compound residue removed by wire or stiff brushing and oil or grease removed with a proprietary degreaser. New concrete should be allowed to cure — for economy roof use the slab should be at least 28 days old. Prime the prepared surface with Nitoproof 110 and let it dry before coating. Stir Nitoproof 120 until homogeneous and apply it evenly in two coats at roughly 2 to 2.5 m2/litre per coat (use the 2.5 m2/litre rate where ASTM C309 water-retention performance is required), allowing the first coat to dry — typically 4 to 8 hours at 20 degrees C for films up to 0.5 mm, longer in cold weather or at higher build. At cracks, lay a stripe coat about 1 mm thick and 50 mm either side, embed Nitoproof Scrim, then overcoat. Critically, protect the finished membrane from daylight and mechanical damage — backfill, screed or board it promptly so the bitumen is never left exposed to UV.
Specifications
| Product type | Single-component, fibre-reinforced bituminous waterproof protective coating |
| Composition | Selected bitumens blended with non-asbestos reinforcing fibres |
| Solids content | Approx. 55% |
| Specific gravity @ 20 C | 1.0 |
| Coverage | Approx. 2 to 2.5 m2/litre per coat (use 2.5 m2/litre for ASTM C309 compliance) |
| Number of coats | 2 coats over Nitoproof 110 primer |
| Primer | Nitoproof 110 |
| Drying time | 4 to 8 hours @ 20 C for thickness up to 0.5 mm (longer at lower temperatures / higher build) |
| Flexibility | Pass (BS 3416) |
| Chemical resistance | Resistant to water, aqueous salt solutions, detergent solutions, mild mineral acid and alkali; not resistant to organic solvents |
| Standards compliance | ASTM D1227:1995 Type 2 Class 1; ASTM C309 (water retention at 2.5 m2/litre); BS 8102; BS 3416 |
| Colour / finish | Black bituminous |
| Pack size | 15 litre container (typical India supply) |
Industry use cases
Basements & below-ground
External tanking of basement retaining walls and raft soffits in commercial and residential builds, protecting structural concrete against ground water and aggressive soils before backfilling.
Water-retaining structures
Internal lining of masonry and concrete water-storage tanks, including potable-water tanks, taking advantage of the asbestos-free, taint-free dried film.
Sandwich construction
Horizontal and vertical damp-proof membranes sandwiched within floor and wall build-ups, giving a concealed, jointless DPM in institutional and industrial buildings.
Infrastructure & foundations
Protective coating to foundations, plinth beams and pile caps in projects across Delhi NCR and Pan-India where the waterproofing is permanently buried.
Roofing (economy / repair)
Low-cost protected roof membranes and patch repairs to felt and asphalt roofs, with Nitoproof Scrim reinforcement bridging cracks before the area is covered.
Frequently asked questions
Is Fosroc Nitoproof 120 suitable for potable-water tanks?
Do I need a primer with Nitoproof 120?
What coverage and how many coats should I allow?
Can Nitoproof 120 be left exposed to sunlight?
How is Nitoproof 120 different from Fosroc’s polyurethane or elastomeric membranes?
How long does each coat take to dry?
How we position Fosroc Nitoproof 120
Nitoproof 120 sits in the middle of Fosroc’s bituminous waterproofing line as the dependable, fibre-reinforced coating for concealed and below-ground work. It is the natural step up from a plain bituminous primer/coating like Nitoproof 110 (which it is in fact applied over), and it pairs with accessories such as Nitoproof Scrim for crack reinforcement. Where the membrane will see UV, foot traffic or large crack movement, the conversation should move to Fosroc’s elastomeric and polyurethane systems — the Nitoproof 600/800/900 membranes or the cementitious Brushbond range — rather than this bituminous grade. Against the wider Indian market, credible alternatives in the same below-ground bituminous niche include Sika’s bituminous coatings (e.g. the Igolflex/SikaProof bituminous range), MBS’s bituminous waterproof coatings, Dr. Fixit’s Bitumen Coat / Primeseal-type products from Pidilite, and STP Limited’s bituminous coatings such as those in the Shalimar/Shalitex line. Our recommendation depends on exposure and detailing: Nitoproof 120 remains a strong, well-proven specification for buried tanking, sandwich DPMs and tank linings, while exposed roofs and decks are better served by a UV-stable elastomeric membrane. Space Arc Engineering, as an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India, can supply genuine Nitoproof 120 with the correct primer and accessories and advise on the right system for your substrate and exposure.
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