Fosroc Nitomortar EL
Trowellable, solvent-free epoxy lining mortar that protects concrete against acids, alkalis, sewage and abrasion in manholes, effluent channels and industrial repair work.
What is it?
A three-component, solvent-free epoxy resin lining mortar reinforced with special silica aggregates, supplied in pre-weighed base, hardener and filler packs for trowel application.
Where is it used?
Manhole rehabilitation, sewer and outfall linings, effluent channels, sewage treatment works and any concrete or masonry structure exposed to chemical attack and abrasion.
Why use it?
It bonds to dry or damp substrates without a primer on most concrete, resists a wide range of acids and alkalis, and develops strength well above the parent concrete so the repair outlasts the structure around it.
How is it applied?
Mechanically mix base and hardener, blend in the full aggregate bag, then trowel onto a clean, sound substrate from 3 mm up to 12 mm per pass on vertical and overhead faces, building thicker sections in layers.
About Fosroc Nitomortar EL
Fosroc Nitomortar EL is a trowellable, abrasion-resistant epoxy lining mortar engineered for the long-term protection of concrete and similar substrates that are in continuous contact with aggressive chemicals. It belongs to Fosroc’s chemically resistant epoxy mortar family within the wider ‘Systematic Approach’ to concrete repair, and is designed specifically for the harsh service conditions found in wastewater and process environments where conventional cementitious repair mortars degrade quickly.
The product is a three-component, solvent-free system. A high-quality epoxy resin base and a matched hardener are combined with a pre-weighed bag of specially graded silica aggregate. The silica filler is what gives the cured mortar its high strength and exceptional resistance to abrasion and impact, while the solvent-free epoxy binder delivers the chemical resistance and the tenacious bond to both dry and damp concrete. Because the components are supplied in fixed, pre-weighed quantities, the mix ratio is controlled on site and there is no scope for the batching errors that undermine repair durability.
A defining characteristic of Nitomortar EL is its ‘hanging’ or non-sag behaviour, which lets applicators build vertical and overhead sections up to 12 mm in a single pass without formwork. For Indian contractors working inside manholes, wet wells, sumps, drainage outfalls and effluent channels, this makes it a practical, fast-turnaround patching and lining material in confined, awkward locations. Once cured, the mortar forms a long-lasting, effectively waterproof barrier that shields the structural concrete from acid generation, alkali attack and the constant scouring that flowing effluent inflicts on invert surfaces.
Space Arc Engineering supplies Nitomortar EL as an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India, with technical guidance on substrate preparation, priming and the correct complementary Fosroc system for each repair scenario.
The technical insight
Nitomortar EL is best understood as a chemical-resistant lining mortar rather than a general structural repair mortar, and specifying it correctly hinges on three numbers from the data sheet. First, build thickness: it is applied from a minimum of 3 mm up to a maximum of 12 mm per coat on vertical and overhead surfaces, with greater depths achieved by successive layers applied 24 to 36 hours apart at 20°C. Exceeding 12 mm in one pass risks sagging, in which case Fosroc directs you to a higher-build product (Nitomortar HB). Second, strength development is rapid and high: tested to BS 6319, the cured mortar reaches a compressive strength of 70 N/mm2, flexural 28 N/mm2 and tensile 12 N/mm2 at just 7 days, comfortably exceeding the parent concrete and the abrasion demands of effluent flow. Third, working time is short and temperature-sensitive: pot life is 2 hours at 20°C but falls to roughly 1 hour at 35°C, so in Indian summer conditions material must be kept shaded or air-conditioned, mixed in small batches and never applied in direct sunlight. The system is largely primer-free on sound concrete because the epoxy bonds directly to dry or damp substrates, but highly porous surfaces or critical build/sag situations should first receive a single coat of Nitocote Primer Sealer, over-coated once it has gelled to surface tack. Crucially, part packs must never be used and solvent must never be added to thin the mortar or lubricate the trowel, as either will compromise the cure.
Where it is used
- Internal lining and rehabilitation of brick, block and concrete manholes and inspection chambers
- Lining of outfalls, drainage channels and effluent/sewage conveyance structures
- Protection of concrete in sewage treatment and pumping works exposed to H2S-driven acid attack
- Repair and lining of invert and benching surfaces subject to abrasion from grit-laden flow
- Chemical-resistant patching of process areas, bund walls and floors in contact with acids and alkalis
- Vertical and overhead reinstatement of chemically attacked concrete without formwork
- Re-profiling and resurfacing of scoured concrete in water and wastewater assets
Key advantages
- Resistant to a wide range of acids, alkalis, industrial chemicals and sewage
- Excellent abrasion and impact resistance from the graded silica aggregate
- Superior bond to virtually all substrates, dry or damp
- No primer required on normal sound concrete surfaces
- Non-sag ‘hanging’ properties allow up to 12 mm vertical/overhead build without formwork
- High early strength (70 N/mm2 compressive at 7 days) minimises downtime
- Pre-weighed three-component packs eliminate site batching errors
- Cured mortar provides a long-lasting, effectively waterproof protective barrier
- Solvent-free and non-flammable in its mortar form
Limitations & considerations
- Maximum 12 mm per coat on vertical/overhead work; thicker sections need multiple layers and Nitomortar HB is preferred for higher build
- Short pot life (about 1 hour at 35°C) demands small batches and shaded storage in Indian heat
- Part packs must never be used; the full pre-weighed base, hardener and aggregate must be mixed together
- Solvent must not be added to thin the mortar or lubricate trowels, as it prevents proper cure
- Must not be exposed to moving water during application; heavy rainfall before set can cause surface scour
- Active water leaks must be stopped first (e.g. with Renderoc Plug or Nitofill injection) before lining
- Higher material cost than cementitious repair mortars, so best reserved for genuinely chemically aggressive exposure
- 12-month shelf life at 30°C, reduced to 4-6 months under high temperature or humidity
Selection & best practice
Prepare the substrate by high-pressure water jetting or light abrasive blasting to remove all unsound, contaminated, oily or laitance-affected material, then wash down and confirm soundness with a pull-off test. Stop any active hydrostatic leaks with Renderoc Plug or Nitofill WS60/UR63 before lining. On highly porous concrete, apply one coat of Nitocote Primer Sealer and over-coat once it gels to surface tack (typically 20 minutes to 4 hours). Mix base and hardener mechanically with a slow-speed drill (350-500 rpm) and spiral paddle for about 5 minutes, then blend in the entire aggregate bag for a further 2-3 minutes; never use part packs. Apply by spatula or steel float, pressing firmly for full compaction, from 3 mm up to 12 mm per pass, and build thicker sections in layers 24-36 hours apart. In hot Indian conditions keep materials shaded, mix only what can be used within the pot life, and never apply in direct sunlight or add solvent.
Specifications
| Product type | Three-component, solvent-free epoxy resin lining mortar with silica aggregate |
| Consistency | Trowellable, non-sag (‘hanging’) for vertical and overhead work |
| Application thickness | 3 mm minimum to 12 mm maximum per coat (greater build in layers) |
| Compressive strength | 70 N/mm2 at 7 days (BS 6319, Pt 2) |
| Flexural strength | 28 N/mm2 at 7 days (BS 6319, Pt 3) |
| Tensile strength | 12 N/mm2 at 7 days (BS 6319, Pt 7) |
| Pot life | 2 hours at 20°C; 1 hour at 35°C |
| Initial hardness | 24 hours at 20°C |
| Full cure | 7 days at 20°C |
| Fresh wet density | Approximately 1750 kg/m3 (fully compacted) |
| Priming | Not required on normal concrete; Nitocote Primer Sealer on highly porous substrates |
| Pack size | 10.0 litre pack (pre-weighed base + hardener + aggregate) |
| Coverage / yield | 3.3 m2 per pack at 3 mm thickness |
| Chemical resistance | Resistant to HCl 30%, H2SO4 17%, H3PO4 25%, NaOH 40%, petrol, bleach, sea water, detergent |
| Shelf life | 12 months at 30°C in original unopened packs (4-6 months if hot/humid) |
Industry use cases
Water & Wastewater Utilities
Lining and rehabilitating municipal manholes, wet wells and outfalls where hydrogen-sulphide-driven acid attack and grit abrasion destroy ordinary cementitious linings.
Sewage & Effluent Treatment Plants
Protecting concrete channels, sumps and benching in STPs and CETPs against mixed acid/alkali chemical exposure and continuous flow scouring.
Industrial & Process Plants
Chemical-resistant patching of bund walls, trenches and floor areas in contact with acids, alkalis and industrial chemicals in chemical, pharma and fertiliser facilities.
Infrastructure & Drainage
Re-profiling abraded invert surfaces and resurfacing chemically attacked concrete in stormwater outfalls and large-diameter drainage structures.
Marine & Coastal Structures
Localised lining of splash-zone and effluent-contact concrete where resistance to sea water and aggressive chemicals is required.
Frequently asked questions
What type of product is Fosroc Nitomortar EL?
How thick can Nitomortar EL be applied in one coat?
Does Nitomortar EL need a primer?
What is the pot life and how does Indian heat affect it?
What strength and chemical resistance does it achieve?
What is the pack size, coverage and shelf life?
How we position Fosroc Nitomortar EL
Nitomortar EL sits in Fosroc’s chemically resistant epoxy mortar tier, above general-purpose cementitious repair mortars and reserved for genuinely aggressive chemical and abrasion exposure such as manholes, sewers and effluent works. Within the Fosroc range it pairs naturally with Renderoc Plug or Nitofill WS60/UR63 for stopping active leaks before lining, Nitocote Primer Sealer where priming is needed, and the Nitocote epoxy and Dekguard protective coatings to bring surrounding concrete up to the same protective standard; where higher single-pass vertical build is required, Nitomortar HB is the sibling product. For standard non-chemical structural repair, Fosroc’s Renderoc hand-placed and spray mortars are the more economical choice. Against the wider Indian market, credible alternatives in the chemical-resistant and epoxy repair space include Sika’s Sikadur and Sikagard chemical-resistant systems, MBS (MB Solutions / former BASF Master Builders) MasterEmaco epoxy mortars, Dr. Fixit’s repair and protective range from Pidilite, and STP’s chemical-resistant linings. Space Arc Engineering, as an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India, can specify Nitomortar EL within a complete, warranty-aligned Fosroc repair system rather than as an isolated product, which is the key advantage of sourcing the genuine material with applicator support.
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