About Fosroc Nitoseal PS200

Fosroc Nitoseal PS200 is a black, two-part, pitch-extended polysulphide joint sealant engineered for horizontal joints in trafficked concrete. It is supplied as a base and a hardener in pre-weighed quantities that are mixed on site and poured directly into the joint, where the material self-levels to give a uniform, neat finish. Once cured, it forms a low-modulus, highly resilient and elastic seal that can absorb the repeated expansion and contraction of pavement and floor joints across a wide range of ambient temperatures.

The “pitch-extended” polysulphide base is what differentiates PS200 from a standard building-grade polysulphide. The pitch component improves resistance to fuels and hydrocarbons, raises resistance to age-hardening, and helps the cured sealant resist the penetration of stones and hard debris that would otherwise be pressed into a softer sealant by passing wheels. This makes it well suited to roads, aprons, hardstandings and industrial floors where Indian site conditions combine high surface temperatures, dust and heavy traffic.

As a pouring (self-levelling) grade, PS200 is designed only for horizontal joints — it is not a gun-grade, non-sag sealant and should not be used on vertical or overhead joints, where a thixotropic product such as a gun-grade polysulphide or polyurethane is required instead. Used together with Fosroc Primer 7, it develops tenacious adhesion to concrete, stone, brickwork and similar substrates. For Space Arc Engineering’s customers across Delhi NCR and Pan-India, PS200 sits in the Fosroc joint-sealing family alongside the Thioflex polysulphide range and the Colpor cold-applied pavement sealants, giving specifiers a verified, brand-backed option for demanding horizontal joints.

The technical insight

The defining technical trait of Nitoseal PS200 is the combination of polysulphide chemistry with a pitch (coal-tar/bitumen-type) extender. Cured polysulphide gives the seal its rubber-like elasticity and excellent recovery, which is why the product is described as low-modulus and highly resilient — it exerts low stress back onto the joint arris as it stretches and compresses, protecting weaker concrete edges. The pitch extension then layers on three field-critical behaviours: strong resistance to hydrocarbon fuels and many chemicals (important on roads, fuelling aprons and workshop floors), high resistance to age-hardening so the seal stays flexible over years of UV and thermal cycling, and enough firmness at the surface to resist indentation and stone pick-up under traffic.

Because it is two-part and chemically curing (base plus hardener) rather than a single-part moisture-cure or hot-melt, the cure is largely independent of ambient humidity and proceeds uniformly through the full joint depth — a real advantage over hot-poured bitumen in deeper joints. The trade-off is that mixing discipline matters: the entire pre-weighed hardener must be blended into the base to achieve correct cure, and pot life is finite once mixed. Primer is not optional. Polysulphide sealants rely on a chemically active primer (Fosroc Primer 7) to develop the durable adhesion that lets the seal survive repeated movement without peeling at the bond line.

Where it is used

• Horizontal expansion and movement joints in concrete roads, highways and service roads
• Pavement, footpath and hardstanding joints in external paved areas
• Airfield aprons, taxiways and runway shoulder joints exposed to fuel
• Parking deck, ramp and podium movement joints in commercial and residential developments
• Warehouse, factory and industrial floor and construction joints in trafficked areas
• Joints in fuelling stations, workshops and bunds exposed to hydrocarbons and chemical spillage
• Saw-cut and construction joints in ground-bearing slabs needing a flush, self-levelling seal

Key advantages

• Low-modulus, highly resilient cured seal that accommodates large cyclic joint movement
• Self-levelling pouring grade gives fast, uniform, neat horizontal joints with low labour
• Good resistance to hydrocarbon fuels and many chemicals from the pitch extension
• High resistance to age-hardening for a long service life under UV and thermal cycling
• Firm enough at the surface to resist penetration of stones and hard debris under traffic
• Two-part chemical cure is largely independent of ambient humidity and cures through full depth
• Pre-weighed base and hardener reduce on-site batching errors
• Develops tenacious adhesion to concrete, stone and brickwork when used with Fosroc Primer 7
• Backed by Fosroc’s documented joint-sealant system and primer for specification confidence

Limitations & considerations

• Pouring (self-levelling) grade only — not suitable for vertical or overhead joints; use a gun-grade non-sag sealant there
• Black only, so it is not intended for decorative or colour-matched architectural joints
• Pitch/coal-tar-extended chemistry may not be acceptable on potable-water or certain food-contact projects — verify suitability with the TDS
• Requires Fosroc Primer 7 and correct surface preparation; skipping primer risks adhesion failure
• Two-part product with a finite pot life once mixed — full hardener must be blended and the mix used promptly
• Correct joint design (width-to-depth ratio and a bond-breaker or backer rod) is essential to allow the seal to flex
• Not a structural product or a waterstop substitute; it seals movement joints, it does not replace embedded PVC/hydrophilic waterstops in water-retaining structures

Selection & best practice

Specifications

Industry use cases

How we position Fosroc Nitoseal PS200

Within the Fosroc range, Nitoseal PS200 is the horizontal, pouring-grade option in the pitch/polysulphide family. It sits close to Thioflex 600, a multi-component gun-and-pouring-grade polysulphide that covers both vertical and horizontal joints, and to the wider Nitoseal range (such as the MS and PU gun-grade sealants) used for vertical movement and building joints. For high-performance, pitch-free trafficked pavement joints — including airport and highway work where coal-tar chemistry is restricted — Fosroc’s Colpor 200PF cold-applied pavement sealant is the usual companion or alternative. Choose PS200 specifically when you need a fuel-resistant, age-stable, self-levelling seal for horizontal trafficked joints and a pitch-extended polysulphide is acceptable. Credible non-Fosroc alternatives a specifier may evaluate include Sika’s Sikaflex polyurethane joint sealants and Sikaflex PRO pavement-joint products, MBCC/Master Builders Solutions MasterSeal joint sealants, and STP (Pidilite) joint-sealing systems. Final selection should always be confirmed against current technical data sheets, the project’s movement and chemical-exposure requirements, and any airport/highway authority restrictions on coal-tar-extended materials. As an authorised Fosroc distributor and applicator, Space Arc Engineering can advise on the right Fosroc system and supply the matching primer for Delhi NCR and Pan-India projects.

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