Fosroc Nitoseal MS60
One-part, low-modulus MS-polymer gun-grade sealant for movement and perimeter joints in concrete, masonry and facades — primerless on most substrates, with 25% movement accommodation.
What is it?
A single-component, low-modulus joint sealant based on silyl-modified polyether (MS / SMP hybrid) chemistry, supplied as a non-sag gun-grade paste that cures by reaction with atmospheric moisture.
Where is it used?
Movement and perimeter joints in concrete, brickwork and blockwork, window and door perimeters, precast panel and facade joints, and non-trafficked floor joints across buildings and infrastructure.
Why use it?
It bonds to most common building substrates without a primer, tolerates 25% joint movement, is paintable and isocyanate-free, can be applied to damp surfaces, and stays UV-stable and colour-fast outdoors.
How is it applied?
Gun-applied into a correctly designed joint over a backer rod / bond breaker at a 2:1 width-to-depth ratio, tooled to a firm concave finish before skinning, typically without primer except in high-movement or immersed joints where Fosroc Primer MS2 is used.
About Fosroc Nitoseal MS60
Fosroc Nitoseal MS60 is a one-part, low-modulus elastomeric joint sealant built on silyl-modified polyether (MS polymer) technology — a hybrid chemistry that combines the elasticity and weathering of polyurethanes with the substrate friendliness and stability of silicones, while avoiding both isocyanates and the staining tendencies of conventional silicones. It is supplied as a smooth, non-slumping (gun-grade) paste in foil sachets / sausages and cartridges, and it cures by reacting with moisture in the air to form a tough, permanently flexible rubber. For Indian projects, that translates into a sealant that is straightforward to specify and apply on busy sites: a single component means no on-site mixing or wastage, and the low-modulus formulation keeps stress on the joint arrises low even when the structure moves. Nitoseal MS60 is designed to seal building movement and perimeter joints rather than to carry traffic, sitting in Fosroc’s Nitoseal family alongside higher-performance and pourable grades. Space Arc Engineering, as an authorised Fosroc distributor and applicator covering Delhi NCR and Pan-India, supplies Nitoseal MS60 together with the associated Fosroc Primer MS2, backer rods and tooling consumables, and offers application support and joint-design guidance so that the product performs to its rated movement capability in service.
The technical insight
The defining property of Nitoseal MS60 is its low-modulus behaviour combined with a 25% movement accommodation factor (MAF), which is what its ISO 11600 Type F25LM and ASTM C920 Class 25, Grade NS, Type S classifications certify. \”Low modulus\” means the cured sealant develops only modest internal stress as it stretches and compresses, so it pulls less aggressively on weak or freshly cured concrete and masonry edges — the usual failure point in movement joints. The 25% MAF means a correctly designed joint can absorb total movement of roughly a quarter of its installed width (the sum of expansion and contraction) without cohesive or adhesive failure, which is why joint sizing matters: a joint expected to move ±5 mm needs to be designed around a 20 mm nominal width. The MS-polymer backbone cures by moisture, so cure proceeds from the surface inward — skinning within about two hours and developing roughly 2 mm of cure depth per 24 hours at 20°C and 50% relative humidity. In India’s monsoon and coastal humidity this surface cure is generally faster, but deep or wide joints still take time to fully cure through, which is the practical reason maximum joint width is capped at 35 mm without referral to Fosroc Technical Services. Because the chemistry is silyl-modified, it is also paint-over-able and bonds to damp (though not running-wet) substrates — a genuine advantage over many polyurethanes on Indian sites where surfaces are rarely bone dry.
Where it is used
- Expansion and contraction movement joints in in-situ and precast concrete
- Perimeter sealing around window and door frames against masonry or concrete
- Construction and control joints in brickwork and blockwork walls
- Joints between precast cladding panels and facade elements (EN 15651-1)
- Non-trafficked internal floor joints in commercial and residential buildings
- Acoustic / sound-insulation sealing of partitions and building elements
- General weather-sealing of joints in concrete, brick and rendered surfaces
- Sealing around pipe and service penetrations through walls and slabs
Key advantages
- Single component — no site mixing, no pot-life waste, faster application
- Low-modulus, 25% MAF (ISO 11600 F25LM) — accommodates real structural movement with low edge stress
- Primerless on most common building substrates, reducing labour and material cost
- Bonds to damp substrates, suiting humid and monsoon-season Indian site conditions
- Isocyanate-free MS-polymer chemistry — lower-odour, environmentally friendlier than PU
- UV resistant and colour stable for exposed external joints
- Paintable and over-coatable, unlike most silicone sealants
- Functions as an acoustic sealant (BS EN ISO 140-3 / 717-1 tested)
- Available in White, Grey and Black with Buff, Anthracite and Rustic Red on request
Limitations & considerations
- Not intended for trafficked floor or pavement joints — use a pourable/trafficable grade such as Colpor or Nitoseal MS600 instead
- 25% MAF only — high-movement joints may need a higher-performance sealant
- Maximum joint width 35 mm without referral to Fosroc Technical Services
- Not for continuous water immersion or hydrostatic situations; intermittently immersed joints require Fosroc Primer MS2
- Not a structural glazing or load-bearing adhesive sealant
- Application temperature limited to 5°C–50°C; deep joints cure slowly (approx. 2 mm/24 h)
- Requires correct joint design (backer rod, 2:1 width:depth) to achieve rated movement
- Not chemically resistant — unsuitable for aggressive chemical or fuel-contact joints
Selection & best practice
Design every moving joint to a width-to-depth ratio of 2:1 with a minimum sealant depth of 5 mm, keeping installed width between 5 mm and 35 mm. Insert a closed-cell polyethylene backer rod (about 25% larger than the joint width) to control sealant depth and act as a bond breaker, so the sealant adheres only to the two opposing faces and can flex freely — never let it bond to the joint base (three-sided adhesion). Substrates must be sound, clean and free of dust, laitance, oil, old sealant and loose material; mechanical preparation (grinding, grit-blasting or wire-brushing on metal) is preferred. No primer is needed on most building substrates, but for joints subject to high movement or intermittent immersion apply Fosroc Primer MS2 and seal between 30 minutes and 4 hours afterwards. Gun the sealant firmly to fill the joint without voids, then tool to a smooth concave profile before the surface skins (within ~2 hours). Apply only between 5°C and 50°C, and confirm the joint movement budget against the 25% MAF before specifying — for wider, trafficked or higher-movement joints, refer to Fosroc Technical Services or step up to a more capable grade.
Specifications
| Product type | One-part, low-modulus joint sealant |
| Chemical basis | Silyl-modified polyether (MS polymer / SMP hybrid) |
| Grade / consistency | Gun-grade, non-sag smooth paste (sag < 3 mm) |
| Cure mechanism | Moisture cure (atmospheric humidity) |
| Movement accommodation factor (MAF) | 25% |
| ISO 11600 classification | Type F25LM (façade, 25%, low modulus) |
| ASTM C920 classification | Type S, Grade NS, Class 25 |
| Other standards | EN 15651-1; BS EN ISO 140-3 & 717-1 (acoustic) |
| Skinning time | Up to 2 hours (ambient dependent) |
| Cure rate | ~2 mm in 24 hours at 20°C / 50% RH |
| Hardness | Shore A > 20 (at 23°C) |
| Application temperature | 5°C to 50°C |
| Service temperature range | -20°C to +70°C |
| Joint width range | 5 mm to 35 mm |
| Joint design (width:depth) | 2:1, minimum depth 5 mm |
| Primer | Primerless on most substrates; Fosroc Primer MS2 for high-movement / immersed joints |
| Colours | White, Grey, Black (Buff, Anthracite, Rustic Red on request) |
| UV / colour stability | Very good; paintable |
| Pack size | 600 ml foil sachet/sausage (box of 10); 380 ml also available |
Industry use cases
Commercial & residential buildings
Sealing window and door perimeter joints and masonry control joints, where its primerless adhesion and paintability speed up facade and fit-out works.
Precast & facade construction
Weather-sealing joints between precast concrete cladding panels and facade elements to EN 15651-1, with UV-stable, colour-fast performance on exposed elevations.
Infrastructure & civil works
Sealing expansion and construction joints in concrete structures such as retaining walls, culverts and non-trafficked decks where low-modulus movement capacity protects joint arrises.
Institutional & acoustic-rated builds
Acoustic sealing of partition and building-element joints in hospitals, schools and offices, leveraging its tested sound-insulation performance.
Industrial & MEP
Sealing around pipe and service penetrations and non-trafficked internal floor joints in plant rooms and warehouses where a flexible, low-odour single-component sealant is preferred.
Frequently asked questions
What type of sealant is Fosroc Nitoseal MS60?
How much joint movement can Nitoseal MS60 accommodate?
Does Nitoseal MS60 need a primer?
What joint sizes and design should be used?
Can Nitoseal MS60 be used on floors and can it be painted?
What colours and pack sizes are available in India?
How is Nitoseal MS60 different from Thioflex 600 or Colpor 200PF?
How we position Fosroc Nitoseal MS60
Within the Fosroc range, Nitoseal MS60 is the easy-to-use, modern MS-polymer choice for general building movement and perimeter joints — primerless, paintable and isocyanate-free. Specifiers needing higher movement or a pourable, trafficable joint should look at Nitoseal MS600 or the Colpor pavement-grade sealants, while Thioflex 600 (two-part polysulphide) remains the traditional option where polysulphide chemistry or specific chemical resistance is called for. Among credible alternatives commonly available in India, Sika’s Sikaflex range (for example Sikaflex AT-Connection / Sikaflex-11FC for hybrid and PU sealants) and MBS / Master Builders Solutions MasterSeal (formerly the BASF MasterSeal NP/SL line) cover the same MS-polymer and polyurethane sealant territory, and STP Limited offers comparable hybrid and PU joint sealants for the domestic market. For most vertical and non-trafficked perimeter and movement joints on concrete, masonry and facades, Nitoseal MS60 is positioned as the convenient, weather-durable workhorse; the decision to move to another product should be driven by higher movement demand, trafficability, immersion or specific chemical-resistance requirements rather than by general sealing performance.
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