Fosroc Supercast Acrylate 100
A water-thin, hydrophilic methacrylate injection gel that penetrates fine cracks and joints, then swells reversibly with moisture to form a permanent, elastic water barrier in concrete and surrounding soil.
What is it?
A hydrophilic, cross-linked methacrylate (acrylate) injection gel that cures in-situ from a water-thin liquid into an elastic, water-swellable seal. It is an injection-grade joint-treatment and waterproofing resin, not a conventional gun- or pour-grade elastomeric joint sealant.
Where is it used?
Injected into leaking construction joints, fine cracks, segment (tubbing) joints, pile heads and the soil/concrete interface of basements, tunnels, shafts, tanks and other water-retaining and below-grade structures.
Why use it?
Its water-like viscosity lets it penetrate cracks and granular soil that thicker resins cannot reach; it then forms a flexible gel that swells reversibly when wet, sealing active leaks while remaining isocyanate-free and suitable for potable-water contact.
How is it applied?
Pumped through a multi-component injection pump (or a cast-in re-injectable hose such as Supercast Injectoseal) into pre-set packers or the hose valves; the components react in the crack/soil to gel within an adjustable, pre-set reaction time.
About Fosroc Supercast Acrylate 100
Fosroc Supercast Acrylate 100 is a hydrophilic, cross-linked methacrylate (acrylate) gel supplied as a multi-component injection system. On site the components are combined and pumped as a liquid that is almost as thin as water; once inside a crack, joint or saturated soil it reacts to form a tough, elastic gel that bonds the void shut and stops water movement. Because the cured gel is hydrophilic, it absorbs moisture and swells, then releases it and contracts as conditions dry — a reversible action that keeps the seal active over wetting and drying cycles rather than shrinking away from the substrate. It is part of Fosroc’s Supercast family of waterstops and joint-sealing systems, sitting alongside the higher-strength three-component Supercast Acrylate 200 and the re-injectable Supercast Injectoseal hose. It is important to be clear about what this product is and is not. Unlike gun-grade or pour-grade joint sealants such as Fosroc Nitoseal, Thioflex or Colpor — which are gunned or poured into a formed, accessible joint at the surface — Acrylate 100 is an injection resin used for remedial leak-sealing and curtain/soil injection, where the seal is created deep inside the structure or the ground behind it. For Indian basement, tunnel, metro, water-treatment and dam-rehabilitation contractors, it is the tool reached for when a construction joint or crack is already leaking and a flexible, deeply-penetrating chemical seal is needed. It is isocyanate-free, which simplifies handling, and is suitable for contact with potable water, making it relevant to drinking-water tanks and reservoirs subject to the usual project-specific certification checks.
The technical insight
The defining property of Supercast Acrylate 100 is its water-like viscosity at the point of injection. Conventional polyurethane and epoxy injection resins are comparatively viscous and struggle to enter hairline cracks or to permeate fine, sandy or silty soils. An acrylate gel of this type flows into those same voids almost as readily as the water it is displacing, which is why it is favoured for “curtain” or “veil” injection behind a wall and for soil consolidation around tunnels and trenches. The cure is a true in-situ gelation: the reaction time is adjustable, so the applicator can set a fast gel for a high-flow active leak or a slower gel to allow deeper migration before set. The cured product is an elastic, hydrophilic gel — it accommodates ongoing minor movement and, crucially, swells reversibly as moisture enters, pressing against the crack faces to resist further ingress, then contracting on drying without permanent loss of seal. It resists a range of organic and inorganic liquids and, being isocyanate-free, avoids the foaming and handling cautions associated with some PU injection grades. When paired with the Supercast Injectoseal re-injectable hose cast into a construction joint, the same chemistry can be introduced and, if needed, re-introduced through the hose valves to seal that joint after the structure is built.
Where it is used
- Sealing active leaks in concrete construction joints in basements, tanks, shafts and tunnels
- Curtain (veil) injection behind retaining walls and basement walls to form a water barrier in the surrounding soil
- Stabilising and waterproofing sandy or silty soils adjacent to tunnels, trenches and excavations
- Sealing fine cracks and the joints of segmental tunnel linings (tubbings) and bored-pile / diaphragm-wall heads
- Re-injection through cast-in re-injectable hoses (e.g. Supercast Injectoseal) to seal construction joints in watertight structures
- Below-ground waterproofing remediation where surface-applied membranes or gun-grade sealants cannot reach the leak path
Key advantages
- Water-like injection viscosity gives excellent penetration into hairline cracks and fine, granular soils that thicker resins cannot enter
- Adjustable reaction/gel time lets the applicator tune set speed to the leak severity and required depth of migration
- Cured gel swells reversibly with moisture and contracts on drying, keeping the seal active through wet/dry cycles
- Elastic, flexible seal accommodates minor ongoing movement at the crack or joint
- Isocyanate-free chemistry, simplifying site handling compared with some polyurethane injection grades
- Suitable for contact with potable water, subject to project certification
- Good resistance to a range of organic and inorganic liquids
- Can be re-injected when used with a Supercast Injectoseal re-injectable hose system
Limitations & considerations
- Not a gun-grade or pour-grade joint sealant — it cannot be applied into an open, formed surface joint like Nitoseal, Thioflex or Colpor; it is an injection resin
- Requires multi-component injection pumping equipment and trained applicators — not a hand-applied product
- Because it is hydrophilic and swells with moisture, performance depends on the seal remaining in a damp environment; behaviour in permanently dry, fully exposed joints differs from a structural sealant
- Exact gel time, viscosity and yield depend on mix proportions, temperature and ground/water conditions and must be set from the current Fosroc datasheet and site trials
- Soil/curtain injection results depend heavily on ground permeability, water pressure and injection technique — not a substitute for correct waterproofing design
- Drinking-water suitability must be confirmed against the relevant project/regional certification, not assumed
Selection & best practice
Treat Acrylate 100 as a designed injection operation, not a patch. Begin by mapping the leak: locate the wet construction joint or crack, establish water pressure and flow, and decide between direct packer injection into the structure or curtain injection into the soil behind it. Set packers along the crack at a spacing matched to the crack width and concrete thickness (typically staggered either side), drilling to intersect the crack at depth. Use a clean, calibrated multi-component injection pump and confirm the mix and reaction time on the current datasheet before starting — set a faster gel for high-flow active leaks and a slower gel where deeper penetration into fine soil is wanted. Inject from the lowest point upward (or in the direction that drives water out ahead of the gel), watching for gel return at adjacent packers to confirm the void is filling. For new construction where future joint sealing is anticipated, cast a Supercast Injectoseal re-injectable hose into the joint so the acrylate can be introduced — and re-introduced — through the hose valves later. Keep the structure damp where practical so the hydrophilic gel stays activated, flush equipment immediately after use, and record packer positions, volumes and pressures for the project file. For an accessible, formed movement joint at the surface, specify a gun- or pour-grade Fosroc sealant (Nitoseal / Thioflex / Colpor) instead — Acrylate 100 is for the leak inside or behind the structure.
Specifications
| Product type | Hydrophilic, cross-linked methacrylate (acrylate) injection gel |
| Family | Fosroc Supercast waterstop & joint-sealing systems |
| Form / grade | Multi-component, low-viscosity injection resin (pumped, not gun/pour grade) |
| Cure mechanism | In-situ chemical gelation to an elastic, water-swellable gel |
| Reaction / gel time | Adjustable / pre-settable by mix proportions (set from current Fosroc datasheet) |
| Viscosity at injection | Water-like (very low) for high penetration into cracks and fine soils |
| Swelling behaviour | Swells reversibly with moisture ingress; contracts on drying |
| Application method | Multi-component injection pump via packers, or via cast-in re-injectable hose (Supercast Injectoseal) |
| Chemical resistance | Resistant to a range of organic and inorganic liquids |
| Isocyanate content | Isocyanate-free |
| Potable water | Suitable for contact with potable water (subject to project certification) |
| Re-injectable | Yes, when used with Supercast Injectoseal hose |
| Typical substrates | Concrete construction joints, fine cracks, segmental linings, pile heads, surrounding granular soil |
Industry use cases
Metro & tunnelling
Sealing leaking segmental (tubbing) joints and cracks in bored tunnel linings, and consolidating/waterproofing fine soils around running tunnels and cross-passages on metro and rail projects.
Basements & deep foundations
Remedial curtain injection behind diaphragm walls and sealing of leaking construction joints, pile heads and cracks in deep basements of commercial and high-rise developments.
Water-retaining structures
Stopping active leaks at construction joints in water tanks, reservoirs and treatment plant structures, where its isocyanate-free, potable-water-contact profile is relevant subject to certification.
Dams, shafts & hydraulic works
Injection sealing of cracks and joints in shafts, spillways and hydraulic structures, and soil/grout-curtain sealing where water pressure demands a deeply penetrating flexible gel.
Infrastructure remediation
Leak-sealing of underpasses, culverts, pump houses and below-grade civil structures during rehabilitation, often through Supercast Injectoseal hoses installed in the original construction joints.
Frequently asked questions
Is Supercast Acrylate 100 a joint sealant like Nitoseal or Thioflex?
Why is its very low viscosity important?
What does “hydrophilic” and “reversible swelling” mean in practice?
How is it applied on site?
Can it be used in drinking-water tanks?
How does it differ from Supercast Acrylate 200?
How we position Fosroc Supercast Acrylate 100
Supercast Acrylate 100 sits in the injection/joint-treatment end of Fosroc’s Supercast range, not in the gun- and pour-grade elastomeric sealant family. For accessible, formed movement and construction joints at the surface, the right Fosroc choices are the polyurethane and polysulphide sealants such as Nitoseal (PU/MS-based gun grades), Thioflex 600 (polysulphide) and Colpor 200PF (pour grade for trafficked pavement joints) — these accommodate cyclic joint movement at an exposed face. Acrylate 100 is instead the answer when water is already finding its way through a crack, a construction joint or the soil behind a structure and you need a deeply-penetrating, flexible, re-activatable chemical seal, typically through packers or a cast-in re-injectable hose (Supercast Injectoseal). Against the wider market, comparable acrylate/PU injection systems include Sika’s injection range (e.g. Sika InjectoCem / Sika injection resins and the SikaFuko re-injectable hose), MBCC/Master Builders Solutions MasterInject and MasterSeal hose systems, and STP Hydrostop injection products — credible alternatives an Indian consultant may evaluate. As an authorised Fosroc distributor and applicator across Delhi NCR and Pan-India, Space Arc Engineering supplies Acrylate 100 alongside the full Supercast waterstop and Nitoseal/Thioflex/Colpor sealant range, and can match the correct grade, packer/hose system and method statement to your basement, tunnel, tank or dam-rehabilitation requirement.
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