Fosroc Nitomortar EN
A solvent-free Novolac epoxy reinstatement mortar built for the harshest chemical and abrasion environments — acid tanks, effluent plants and heavy-duty industrial floors.
What is it?
A three-component, solvent-free Novolac epoxy repair mortar that cures to roughly twice the strength of good-quality concrete, with exceptional resistance to acids, alkalis and abrasion.
Where is it used?
Acid and chemical tanks, effluent and ETP structures, sea walls, bund walls, industrial and warehouse floors, loading bays and as a high-strength bedding mortar.
Why use it?
It combines structural compressive strength (70 N/mm2 at 7 days) with Novolac-grade chemical resistance and fast strength gain, so aggressive-environment repairs can be reinstated and returned to service quickly.
How is it applied?
Onto a Nitoprime 25 primed substrate (with Nitozinc Primer on exposed steel), trowel- or hand-applied 5-50 mm thick horizontally and up to 12 mm vertically, then closed with a steel trowel.
About Fosroc Nitomortar EN
Fosroc Nitomortar EN is a high-performance concrete reinstatement mortar engineered for situations where ordinary cementitious or standard epoxy repairs simply will not survive. It is based on a solvent-free Novolac epoxy resin system blended with specially graded silica aggregates, supplied as a pre-weighed three-component pack (base, hardener and aggregate) that is mixed on site immediately before use. The “EN” in the name refers to its Novolac (epoxy-novolac) chemistry, which is the key reason this product sits at the top end of Fosroc’s epoxy mortar range for chemical durability.
In practical terms, Nitomortar EN is used for the fast and permanent reinstatement of concrete in places where high strength, abrasion resistance and chemical resistance all have to be delivered at once. Typical settings in India include effluent treatment plants, pickling and acid storage tanks, chemical process floors, dairy and food-processing wet areas, fertiliser and pharmaceutical plants, sea walls and coastal structures, and heavily trafficked industrial and warehouse floors. It also performs well as a high-strength bedding mortar and, in certain cases, can be applied to metal substrates (Fosroc advise confirming this with their local office for the specific situation).
The cured mortar is dense and highly impermeable when fully compacted, which is what gives it its protective quality — it physically slows the ingress of aggressive liquids toward the concrete and embedded reinforcement. It is designed primarily for horizontal repairs, where it can be built up to 50 mm in a single pass, but it can also be worked vertically up to about 12 mm per application. For India’s repair-and-rehabilitation contractors, consultants and plant maintenance engineers, Nitomortar EN is the product to specify when a repair has to be both load-bearing and chemically bulletproof, rather than choosing between the two.
The technical insight
The defining feature of Nitomortar EN is its Novolac epoxy backbone. Standard bisphenol-A epoxy mortars (such as Fosroc’s own Nitomortar S) are excellent general-purpose chemical-resistant repair materials, but Novolac epoxies carry a higher cross-link density and aromatic ring content, which translates into markedly better resistance to strong acids, oxidising chemicals and elevated-temperature chemical exposure. That is the technical justification for choosing EN over a conventional epoxy mortar: it is formulated specifically for the most aggressive service conditions.
The published India TDS values are strong: compressive strength of 70 N/mm2 at 7 days (BS 6319 Part 2), flexural strength of 18 N/mm2 at 7 days (BS 6319 Part 3), tensile strength of 10 N/mm2 at 7 days (ASTM C308) and a compressive elastic modulus greater than 20 GPa, at a fresh wet density of approximately 2000 kg/m3. Pot life is short — around 20 minutes at 35C — which is the trade-off for fast strength gain; initial hardness is reached in about 24 hours and full cure in 7 days. The chemical-resistance schedule confirms the Novolac advantage: tested blocks immersed at 20C are rated resistant to sulphuric acid (10%), hydrochloric acid (18%), nitric acid (10%), phosphoric acid (50%), citric, tartaric and lactic acids, sodium hydroxide (50%), saturated sugar solutions, diesel, petrol and hydrocarbons. The correct primer system is critical to performance: Nitoprime 25 on the prepared concrete substrate and Nitozinc Primer on cleaned, exposed reinforcement, with Nitoflor Sol used as the tool-cleaning solvent.
Where it is used
- Lining and patch repair of acid, pickling and chemical storage tanks
- Effluent treatment plant (ETP/STP) channels, sumps and aggressive wastewater structures
- Industrial, warehouse and loading-bay floors subject to heavy traffic and abrasion
- Sea walls, jetties, bund walls and other coastal/marine concrete in aggressive exposure
- Food, dairy, brewery and pharmaceutical wet-process floors exposed to organic acids
- Fertiliser, chemical and process-plant floors and plinths
- High-strength bedding mortar for machine bases, rails and heavy fixings
- Emergency structural repairs where rapid return to service is essential
Key advantages
- Novolac epoxy chemistry gives resistance to a very wide range of acids, alkalis, fuels and industrial chemicals
- High ultimate strength (70 N/mm2 compressive) — typically about twice as strong as good-quality concrete and suitable for structural repair
- Rapid early strength gain minimises downtime and supports emergency repairs
- Excellent abrasion resistance from graded silica aggregate, ideal for heavy-traffic floors
- Solvent-free, low-odour and non-flammable in mortar form — safer for confined plant areas
- Pre-weighed three-component packs ensure consistent on-site mixing with no batching guesswork
- Builds up to 50 mm horizontally in a single pass without formwork
- Low permeability when fully compacted, protecting both the concrete and embedded steel
Limitations & considerations
- Very short pot life (around 20 minutes at 35C) demands organised work and small batches in Indian summer conditions
- Vertical build is limited to about 12 mm per pass; thicker overhead/vertical work needs layering or a dedicated product such as Nitomortar HB
- Minimum applied thickness is 5 mm — not suitable for thin feather-edged or skim repairs
- Requires a primer system (Nitoprime 25, plus Nitozinc Primer on steel); cannot simply be trowelled onto bare concrete
- Significantly higher material cost than cementitious repair mortars — best reserved for genuinely aggressive environments
- Strict, dust-free substrate preparation (scabbling/grit blasting to a square 5 mm edge) is essential for adhesion
- Epoxy systems are sensitive to application temperature; pot life and cure shift with ambient and substrate heat
- Pack must be used whole — part-pack mixing is not permitted, so estimating quantities accurately matters
Selection & best practice
Plan the job around the short pot life. In Indian field conditions, prepare the substrate fully before opening any pack: scabble or grit-blast to remove laitance, saw-cut the repair perimeter to at least 5 mm to give a square edge (never feather-edge), and break out to a minimum 5 mm depth. Clean exposed reinforcement to bright metal and prime it with Nitozinc Primer within 3 hours, then prime the concrete with Nitoprime 25 and apply Nitomortar EN while the primer is gelled but still tacky (typically 30 minutes to 4 hours later — re-prime if it has cured hard). Mix only complete packs, never part packs, and only as much as the crew can place within the pot life; in hot weather, work in shade and keep materials cool. Apply by wood float, press firmly for full compaction, and finish to a tight surface with a steel trowel without overworking. For larger areas use a checkerboard sequence, and for surrounding zones consider overcoating with the Nitocote or Dekguard range (apply Nitocote within 24 hours; allow Nitomortar EN to reach at least 3 days before Dekguard). Always confirm chemical compatibility and metal-substrate suitability with Space Arc’s technical team for the specific exposure.
Specifications
| Chemical type / system | Solvent-free Novolac (epoxy-novolac) resin mortar with graded silica aggregate |
| Composition | Three components, pre-weighed (base + hardener + aggregate), single grade |
| Compressive strength | 70 N/mm2 at 7 days (BS 6319 Part 2) |
| Flexural strength | 18 N/mm2 at 7 days (BS 6319 Part 3) |
| Tensile strength | 10 N/mm2 at 7 days (ASTM C308) |
| Compressive elastic modulus | Greater than 20 GPa |
| Fresh wet density | Approximately 2000 kg/m3 |
| Pot life | Approximately 20 minutes at 35C |
| Initial hardness / full cure | Initial hardness ~24 hours; full cure 7 days |
| Applied thickness | 5-50 mm horizontal; up to 12 mm vertical per single application (5 mm minimum) |
| Primer system | Nitoprime 25 (concrete substrate); Nitozinc Primer (exposed steel) |
| Pack size | 10 litre pack |
| Coverage | Approximately 2 m2 per pack at 5 mm thickness (theoretical) |
| Chemical resistance | Resistant to H2SO4 10%, HCl 18%, HNO3 10%, H3PO4 50%, NaOH 50%, organic acids, fuels and hydrocarbons |
| Reaction to fire | Cured mortar is non-flammable (primers/solvent are flammable) |
| Shelf life | 12 months at 30C in dry, unopened original packs |
| TDS reference | Fosroc India IINDIA/2024/0441/B |
Industry use cases
Chemical & process plants
Reinstating acid tank floors, pickling lines and chemical process slabs where strong-acid resistance is non-negotiable and the area must return to service quickly.
Water & wastewater (ETP/STP)
Repairing effluent channels, sumps and tank walls attacked by sulphates, acids and biogenic corrosion in treatment plants across industrial estates.
Marine & coastal
Patch repair of sea walls, jetties and splash-zone concrete in coastal cities where chloride and abrasion attack are severe.
Food, dairy & pharma
Reinstating wet-process and washdown floors exposed to lactic, citric and other organic acids while meeting hygiene and durability needs.
Heavy industry & logistics
Restoring abrasion-worn industrial floors, loading bays and forklift aisles where impact and traffic have spalled the concrete.
Plant maintenance & emergency repair
Used as a high-strength bedding mortar for machine bases and for fast emergency structural repairs during short maintenance shutdowns.
Frequently asked questions
What makes Nitomortar EN different from Nitomortar S?
What is the compressive strength and how fast does it gain strength?
How thick can Nitomortar EN be applied in one pass?
Does it need a primer, and which one?
What pack size and coverage should I plan for?
Is Nitomortar EN suitable for Indian summer site conditions?
How we position Fosroc Nitomortar EN
Within Fosroc’s concrete-repair range, Nitomortar EN is the chemical-resistance flagship of the epoxy mortar family. Step down to Nitomortar S for general high-strength epoxy reinstatement where strong-acid exposure is not the driver, or to Nitomortar FC for thin fairing and surface defects. For vertical and overhead repairs choose Nitomortar HB (lightweight, high-build), and where a cementitious rather than epoxy system is preferred — for large-volume structural repairs or where overcoating breathability matters — the Renderoc range (Renderoc HB, RG micro-concrete) is the natural counterpart. The repair system is typically completed with Nitoprime 25 and Nitozinc Primer, and protected with the Nitocote epoxy or Dekguard anti-carbonation coatings. Against the wider Indian market, credible alternatives in the Novolac/chemical-resistant epoxy mortar space include Sika’s MonoTop and Sikadur epoxy mortars, MBS (MC-Bauchemie) Nafufill and Emcekrete systems, Dr. Fixit’s epoxy repair mortars for less aggressive duty, and STP (Sika-owned) products for waterproofing-led repairs. Nitomortar EN earns its premium specifically where strong-acid and abrasion resistance must coexist with structural strength; for milder environments a standard epoxy or polymer-modified cementitious mortar is usually more cost-effective. As an authorised Fosroc distributor and applicator serving Delhi NCR and Pan-India, Space Arc Engineering can help match the right grade to your exposure conditions and supply the complete primer-mortar-coating system.
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