Sika SikaFuko VT-1
A re-injectable, integral-valve injection hose cast into construction joints so watertight structures can be sealed on demand, and sealed again, without breaking out concrete.
What is it?
A yellow PVC injection hose with neoprene valve strips that is fixed into concrete construction joints and later injected with resin or microfine cement to seal any leak path.
Where is it used?
Kicker and day-work joints in water tanks, basements, lift pits, tunnels, dams and other structures where post-cast leak access is impractical.
Why use it?
Because it is re-injectable through acrylate or microfine cement, the same joint can be re-sealed months or years later without demolition, making it a reliable backup to passive waterstops.
How is it applied?
The hose is clipped tightly against the fresh joint surface with inlet/outlet leads brought to accessible points, cast in, then injected only if and when a leak appears.
About Sika SikaFuko VT-1
SikaFuko VT-1 is Sika’s re-injectable injection hose for sealing construction joints in structures that must stay watertight. Rather than relying on a single passive barrier, it embeds an injectable circuit directly at the joint. The hose is fixed against the hardened concrete before the next pour is cast around it, with feed lines led out to boxes or accessible points. If water later finds a path through the joint, an applicator connects to those leads and pumps injection resin or cement grout through the hose, which distributes the material evenly along the joint and seals the void from within.
What sets the VT-1 apart from a simple grout tube is its valve construction. The hose is built from a high-strength PVC core carrying an internal injection channel, with lateral grooves covered by compressible neoprene profile strips that act as one-way valves, all held by a fine nylon mesh. Injection medium is forced out through these valves under pressure; when injection stops, the valves close again. Used with acrylate resin or microfine cement suspension, that closing action leaves the channel free for repeat injection, so a single joint can be treated more than once over the life of the structure. This makes VT-1 a genuine serviceable system, not a one-shot detail that is spent after its first use.
The technical insight
The performance comes down to controlled, valve-governed distribution. The PVC core (Shore A 85 ±3, tensile strength at least 14 N/mm²) holds the injection channel open against concrete pressure, while the soft neoprene profile strips (Shore A 20 ±5, elongation over 300%) sit over staggered lateral openings. During injection the medium travels the length of the channel and is pushed out uniformly through these valve openings into the joint, rather than escaping all at once at the nearest weak point. When pressure is released the compressible strips reseat and, with non-setting acrylate or microfine cement, the channel stays clear for a further injection. The system is rated to resist water pressure of up to 10 bar, equivalent to roughly a 100 m head, which covers the vast majority of buried and immersed structures in Indian practice.
Where it is used
- Horizontal kicker joints between raft/base slab and walls in basements and tanks
- Vertical construction (day-work) joints in water-retaining walls
- Water treatment tanks, clear-water reservoirs and STP structures
- Underground metro and utility tunnels, cut-and-cover sections
- Lift pits, machine pits and other deep pockets below the water table
- Dams, spillways and hydraulic structures
- Marine and coastal structures exposed to saltwater ingress
- Repair and refurbishment joints where a re-sealable backup is specified
Key advantages
- Re-injectable with acrylate resin or microfine cement, so the same joint can be sealed more than once
- Valve technique distributes injection medium evenly along the full joint length
- Seals leaks from within, avoiding demolition of finished or immersed concrete
- Rated to resist water pressure up to 10 bar (~100 m head)
- Works as a reliable backup in combination with passive waterstops
- Compact 6 mm internal / 13.5 mm external hose fixes easily into congested reinforcement
- Supplied as a combi-pack with clips, plugs and accessories for a complete install
- Long 48-month shelf life in sealed packaging for stock-and-hold projects
Limitations & considerations
- Single injection only when polyurethane or epoxy resins are used; multiple injections need acrylate or microfine cement
- Performance depends entirely on correct fixing; gaps or loose clips let medium escape and leave voids
- Feed and return leads must be brought to accessible points before casting, so it demands planning at design stage
- It is a joint-sealing system, not a substitute for sound concrete, cover or overall waterproofing design
- Injection equipment and a trained applicator are required; it is not a self-application product
- Hose sections should be kept to sensible lengths so injection pressure reaches the full run evenly
Selection & best practice
Fix the hose tightly and continuously against the cleaned, hardened joint surface using the supplied clips at close spacing so it stays in full contact during the next pour, keeping it back from the concrete edge to maintain cover. Bring inlet and outlet leads out to marked, accessible boxes and label every circuit, keeping individual runs to a moderate length so injection pressure carries the medium along the whole section. Avoid crossing hose over itself and protect the leads during casting. If a leak later appears, inject with acrylate resin or microfine cement where re-injection may be needed, reserving polyurethane or epoxy for one-time seals. Store the combi-pack sealed and dry between +5 C and +35 C until installation.
Specifications
| Product type | Re-injectable valve injection hose for construction joints |
| Core material | High-strength yellow PVC with neoprene valve strips and nylon mesh |
| Internal diameter | 6 mm |
| External diameter | 13.5 mm |
| Core hardness / strips | Shore A 85 ±3 core; Shore A 20 ±5 profile strips |
| Tensile strength (core) | ≥ 14 N/mm² |
| Water pressure resistance | Up to 10 bar (approx. 100 m head) |
| Injection media | Acrylate resin or microfine cement (re-injectable); PU or epoxy (single injection) |
| Pack / shelf life | 200 m combi-pack with accessories; 48 months sealed, +5 C to +35 C |
Industry use cases
Water & Wastewater
Sealing kicker and wall joints in clear-water tanks, STP structures and treatment basins where re-injection avoids draining and demolition.
Infrastructure & Tunnels
Backup joint sealing in metro, cut-and-cover and utility tunnels that must stay dry under sustained ground-water head.
Commercial Basements
Protecting raft-to-wall and day-work joints in deep basements and lift pits below the water table in Delhi NCR and other high-water-table zones.
Marine & Coastal
Guarding construction joints against saltwater ingress in coastal and hydraulic structures where later access is impossible.
Frequently asked questions
What makes SikaFuko VT-1 re-injectable when many injection hoses are not?
Do I inject the hose during construction?
Which injection medium should I specify?
How much water pressure can it handle?
Can it replace a conventional waterstop?
What comes in the combi-pack?
How we position Sika SikaFuko VT-1
Specify SikaFuko VT-1 where a construction joint must be re-sealable long after the concrete is cast. Within the Sika family it pairs naturally with SikaSwell S-2 sealant and SikaSwell A profiles for the primary passive seal, while Sika Injection-201 IN and Sika Injection-306 are the injection resins pumped through the hose. As an authorised distributor and applicator across Delhi NCR and Pan-India, Space Arc also supplies equivalent systems from other brands, so we can match the specification to the medium, joint detail and budget on your project. Where a specifier prefers the Fosroc route, Supercast Injectoseal is the direct counterpart from the Fosroc Supercast waterstop range.
Fosroc Supercast Injectoseal — Choose the Fosroc option when the rest of the joint waterproofing is already built around the Fosroc Supercast waterstop range and you want a single-brand, single-warranty package.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.