About Dr. Fixit Feviseal HY 100

Feviseal HY 100 sits in Pidilite’s hybrid sealant line under the Dr. Fixit / Feviseal umbrella, built on silyl-modified (MS) polymer chemistry rather than the polyurethane or acetoxy-silicone bases most Indian site teams grew up on. In practice that means it cures by reacting with atmospheric moisture into a flexible, low-modulus rubber — without the isocyanate content that makes conventional PU sealants a health-and-disposal concern on site, and without the surface-staining tendencies of ordinary silicones. Pidilite positions it specifically for movement joints: the ±25% Movement Accommodation Factor and ISO 11600 Type F25LM / ASTM C920 Type S, Grade NS, Class 25 NT classification put it in the same performance bracket as premium imported MS sealants, at a price point Indian contractors can actually specify at scale.

For Space Arc’s project sites across Delhi NCR, HY 100 earns its place wherever a joint genuinely needs to move — expansion joints in RCC frames, gaps between precast panels, tile-to-tile or brick-to-marble junctions, and repair of hairline, non-moving concrete cracks. It ships as a 600 ml sausage meant for gun application, not a retail cartridge for one-off patch jobs, so we typically spec it where a few dozen to a few hundred linear metres of joint need sealing in a single mobilisation. Because it tolerates a damp (not wet) substrate and rarely needs a primer, site crews lose less time waiting for joints to dry out between monsoon showers — a real consideration on NCR sites between June and September.

The technical insight

The “HY” stands for hybrid: Feviseal HY 100 blends the elasticity and adhesion range of polyurethane with the UV stability and low dirt pick-up of silicone, in a single silyl-modified polyether backbone. Because the cure reaction doesn’t rely on isocyanate-solvent crosslinking, there’s little risk of bubble formation in humid weather or the yellowing some PU sealants show after a few Delhi summers. At Shore A 22 ± 6 it stays genuinely soft — this is a low-modulus product engineered to absorb joint movement rather than resist it, which is exactly the property that keeps a sealed expansion joint from tearing away at the bond line after repeated thermal cycles rather than a hardness figure for its own sake.

Where it is used

• Sealing expansion and construction joints in high-rise buildings, basements and floorings
• Sealing joints between precast concrete panels on fast-track builds
• Sealing joints between tiles, bricks and marble surfaces (subject to a compatibility trial)
• Sealing joints in metal container and cladding finishing work
• Repair and sealing of non-moving (dormant) concrete cracks and control joints
• Perimeter sealing around window and door frames in general construction
• Joint sealing on podium decks and basement walls where damp-tolerance matters
• General-purpose elastomeric jointing needing primerless bond to concrete, masonry and metal

Key advantages

• Isocyanate- and solvent-free hybrid chemistry — a lighter health-and-safety footprint on site than PU sealants
• Primerless adhesion to most common construction substrates, saving prep time
• Damp-surface tolerant — can be applied without waiting for a bone-dry joint
• High UV and aggressive-atmosphere resistance for long-term exposed use
• Low dirt pick-up and non-staining, including hydrophobic staining, so light facades stay cleaner
• Wide service temperature range of -40°C to +100°C suits extreme Indian site conditions
• Good low-temperature gunnability with no bubble formation during application
• Genuine ±25% movement accommodation for real expansion/contraction joints

Limitations & considerations

• Sold only as a 600 ml sausage — needs a compatible sausage gun, not geared for small retail or DIY jobs
• Not for continuous immersion — unsuitable for swimming pools, spas or constantly salt-water-immersed joints
• Incompatible with PE, PP, Teflon, neoprene and bituminous surfaces
• Not intended for structural glazing applications
• Paint compatibility, especially with alkyd paints, must be site-tested before overcoating
• Manufacturer flags caution on natural-stone joints — always trial on the actual stone before committing

Selection & best practice

Specifications

Industry use cases

How we position Dr. Fixit Feviseal HY 100

Within the Dr. Fixit / Feviseal family, HY 100 is the go-to hybrid for movement joints; for higher-traffic floor joints Space Arc pairs it with heavier-duty Dr. Fixit crack and floor-joint systems, and where the scope is pure waterproofing membrane work the job routes to the core Dr. Fixit range rather than Feviseal. Where a specification calls for an alternative brand, Fosroc’s Nitoseal MS60 is the closest genuine equivalent — the same low-modulus MS-polymer chemistry and the same ISO 11600 F25LM / ASTM C920 Class 25 classification — and is worth specifying instead when a project is already standardised on Fosroc systems or needs Fosroc’s own facade-sealant documentation trail.

Related Sealants & Joint Treatment products

View all Sealants & Joint Treatment products →