Fosroc Nitocote NT402
Tar-free, 100% solids two-pack epoxy coating that delivers an impermeable, chemically resistant barrier for buried and water-retaining concrete — supplied and applied by Space Arc Engineering across Delhi NCR and Pan-India.
What is it?
A two-pack, 100% solids, tar-free epoxy protective coating (base + hardener) that cures to a tough, impermeable film on concrete and steel.
Where is it used?
Buried and water-retaining concrete — seawater intake tanks, channels, effluent sumps, basements, foundations and industrial floors exposed to chemicals or abrasion.
Why use it?
It waterproofs and protects concrete against aggressive ground, water and chemical attack without coal tar or VOCs, and works primerless to save a coat.
How is it applied?
Surface prepared clean and sound, base and hardener mixed in pre-weighed packs, then applied by brush, roller or spray in two coats at 200 microns WFT each.
About Fosroc Nitocote NT402
Fosroc Nitocote NT402 is a two-pack protective coating built on selected epoxy resins, supplied as a 100% solids, tar-free system in pre-weighed base and hardener packs that are mixed on site and used immediately. It cures to a continuous, impermeable film that shields concrete and steel from water ingress, aggressive ground conditions and a wide range of chemicals.
The product sits in Fosroc’s Nitocote family of protective coatings, but it differs from the older coal-tar epoxies in one important respect: it contains no coal tar, pitch or aromatic hydrocarbons, and no VOCs. For Indian projects where environmental compliance, applicator health and odour during enclosed-space work are real concerns, that makes NT402 a cleaner, more specifier-friendly choice than traditional tar-extended coatings while still delivering comparable waterproofing and chemical resistance.
A key practical advantage is that NT402 is a primerless system. On suitably prepared concrete the coating bonds directly without a separate primer coat, which removes a material and a labour step from the cycle. It is applied as a minimum two-coat system to guarantee a full, unbroken film, with each coat laid at not less than 200 microns wet film thickness. Because it is 100% solids, what you apply wet is essentially what you keep dry — there is negligible solvent loss and shrinkage, so build is predictable.
For contractors and consultants in India, NT402 is most relevant wherever concrete is permanently wet, buried, or in contact with seawater, effluent or chemicals — for example seawater pump-house tanks, cooling-water channels and intakes, sewage and effluent treatment structures, basement retaining walls, pile caps and foundations in aggressive soils, and industrial floors and bunds needing chemical and abrasion resistance. It is available in Light grey, Dark grey, Black, Brick red and Sage Green, allowing colour-coding of zones or a more presentable finish than black tar coatings.
The technical insight
The defining technical feature of Nitocote NT402 is the combination of a 100% solids formulation with a tar-free epoxy chemistry. Because there is no solvent or water carrier, the wet film converts almost entirely to dry film — a 200-micron WFT coat gives roughly 200 microns of dry film — so a standard two-coat application builds toward a substantial, void-free barrier rather than the thin residual film you get from high-solvent products. That density is what gives the coating its impermeability and its resistance to hydrostatic and ground-water pressure on buried structures. Curing is by epoxy-amine reaction and is temperature dependent: full cure is reached in around 4 days at 23 degrees C and accelerates to about 2 days at 35 degrees C, so in Indian summer conditions the cycle is fast, while in cooler weather (down to 5 degrees C) materials should be warmed and cure time extended. The trade-off inherent to all epoxies applies — surfaces must be genuinely dry and clean for the primerless bond to develop, and the cured film, while chemically tough, will chalk and lose gloss under direct UV, which is why it is positioned for buried, immersed and interior service rather than exposed external faces.
Where it is used
- Protective and waterproof lining for seawater intake tanks, channels and pump-house structures
- Buried and water-retaining concrete: basement retaining walls, foundations, pile caps and rafts in aggressive soils
- Sewage, effluent and water-treatment tanks, sumps and channels requiring chemical resistance
- Industrial floors, plinths and bund walls exposed to chemicals and abrasion
- Corrosion-protection barrier over concrete in chemical plants, fertiliser units and process areas
- Protection of concrete against sulphate-bearing and contaminated ground water
Key advantages
- Tar-free and VOC-free — no coal tar, pitch or aromatic hydrocarbons, cleaner for applicators and enclosed-space work
- 100% solids — negligible shrinkage, predictable film build and high effective coverage
- Primerless system on prepared concrete — saves a coat in materials and labour
- Excellent chemical and abrasion resistance across a broad range of acids and alkalis
- Forms an impermeable, waterproof barrier well suited to buried and immersed concrete
- Does not support bacterial growth — useful for effluent and water-handling structures
- Supplied in pre-weighed packs for reliable on-site mixing, with five colour options for zoning
Limitations & considerations
- Not for potable (drinking) water contact — use a WRAS/IS-approved potable-water grade instead
- UV exposure causes chalking and gloss loss; not intended as a finished external weathercoat
- Epoxy cure slows markedly below about 15 degrees C and stalls in damp or condensing conditions
- Substrate must be clean, sound and dry — bond and performance depend heavily on surface preparation
- Limited working time once base and hardener are mixed; mix only what can be used in the pot life
- Bulk 500 kg packs have a short shelf life (about 3 months) versus 12 months for smaller packs
- Not a structural crack-bridging membrane — moving or live cracks need a dedicated flexible system
Selection & best practice
Begin with thorough surface preparation: concrete must be fully cured, sound and clean, with laitance, curing compounds, dust, oil and loose material removed — grit blasting or mechanical abrasion gives the best key. The substrate must be dry, as residual moisture compromises the primerless epoxy bond. Mix each pre-weighed pack in full (base into hardener) with a slow-speed drill and paddle until uniform; never split packs by eye. Apply by brush, roller or airless spray in a minimum of two coats, each at not less than 200 microns WFT, allowing the recommended overcoat interval between coats and ensuring the first coat is touch-dry but within the overcoat window. Work within 5 to 35 degrees C; in summer keep unmixed material out of direct sun, and in cool weather warm the material and extend cure time. Mix only the quantity that can be laid within the pot life, and protect freshly coated surfaces from water and traffic until cured. Always follow the current Fosroc TDS and your project specification, and engage an authorised applicator such as Space Arc Engineering for immersion and buried-concrete work.
Specifications
| Product type | Two-pack, tar-free, 100% solids epoxy protective coating |
| Components | Base + Hardener, supplied in pre-weighed packs |
| Coverage | 5.0 m2/litre at 200 microns wet film thickness per coat |
| Wet film thickness | 200 microns per coat (minimum), can be increased for exposure |
| Number of coats | Minimum 2 coats for a full, unbroken film |
| Cure (full) | Approx. 4 days at 23 degrees C / 2 days at 35 degrees C |
| Application temperature | 5 degrees C to 35 degrees C |
| Application methods | Brush, roller or spray |
| Primer | Primerless system on prepared concrete |
| Colours | Light grey, Dark grey, Black, Brick red, Sage Green |
| Pack sizes | 10 litre packs; 500 kg bulk; ~15 kg base+hardener packs (region-dependent) |
| Shelf life | 12 months (10 litre packs); approx. 3 months (500 kg bulk), stored below 35 degrees C |
| VOC / tar content | No VOC; free of coal tar, pitch and aromatic hydrocarbons |
Industry use cases
Power & desalination
Lining seawater intake tanks, cooling-water channels and pump-house concrete against chloride-rich water and abrasion.
Water & wastewater
Protecting sewage and effluent treatment tanks, sumps and channels from chemical attack and bacterial growth.
Infrastructure & basements
Waterproofing buried retaining walls, foundations and pile caps in aggressive or sulphate-bearing ground water.
Chemical & fertiliser plants
Coating process floors, bunds and plinths needing resistance to acids, alkalis and spillage abrasion.
Industrial flooring
Providing a tough, chemically resistant barrier over concrete floors and service areas in manufacturing units.
Frequently asked questions
Is Fosroc Nitocote NT402 a coal-tar epoxy?
What coverage and thickness should I plan for?
Does NT402 need a primer?
Can Nitocote NT402 be used in drinking-water tanks?
How long does it take to cure in Indian conditions?
Where can I buy Nitocote NT402 in Delhi NCR / India?
How we position Fosroc Nitocote NT402
Within the Fosroc range, Nitocote NT402 is the clean, tar-free counterpart to coal-tar epoxy coatings such as Nitocote ET402/ET402E, and complements Nitocote EP405 (a non-toxic epoxy protective coating) and the broader Nitoproof and Brushbond waterproofing lines; on buried concrete it is frequently specified alongside Fosroc’s Conplast admixtures and Renderoc/Nitomortar repair mortars as part of a complete durability system. Against competitor products, NT402 competes with Sika’s Sikagard and Icoment/Sikalastic protective coatings, MBS (MYK Schomburg) epoxy and bituminous coating systems, Dr. Fixit’s Newcoat/Roofseal and epoxy protective ranges from Pidilite, and STP’s bituminous and epoxy coatings — each of which a consultant may consider as an equivalent for buried or chemical-exposure concrete. NT402’s particular strengths in that field are its 100% solids, tar-free chemistry and primerless application; where a project needs UV-stable external finishes, crack-bridging flexibility or potable-water approval, a different product (including other Fosroc or competitor grades) should be specified instead. As an authorised Fosroc distributor and applicator, Space Arc Engineering helps specifiers and contractors in Delhi NCR and across India match the right coating to the exposure rather than defaulting to a single product.
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