Sika Sikaflex-118 Extreme Grab
A one-part silane-terminated polymer adhesive with exceptionally high initial grab, letting you bond heavy elements to almost any substrate without temporary props or mechanical fixings.
What is it?
A one-component, moisture-curing construction adhesive based on silane-terminated polymer (STP hybrid) chemistry, engineered for very high initial tack.
Where is it used?
Interior and exterior bonding of facade elements, stone, ceramic, metal, glass, mirrors, timber and signage onto concrete, masonry and most common building substrates.
Why use it?
It holds heavy components in place immediately after application, so temporary supports, clamps and drilled fixings can often be eliminated, saving labour and speeding up the sequence.
How is it applied?
Gun-applied from a 290 ml cartridge as dabs or a continuous bead onto a clean, sound surface, then the element is positioned and pressed home within the open time.
About Sika Sikaflex-118 Extreme Grab
Sikaflex-118 Extreme Grab is Sika’s answer to a recurring site problem: how do you hold a heavy element against a wall or soffit while the adhesive cures, without a forest of props, wedges and temporary screws? Built on silane-terminated polymer (STP) technology, it develops an unusually strong initial grip the moment two surfaces are pressed together, so mirrors, stone slips, metal profiles and facade trims stay put on their own. It is a genuine hybrid, combining the strong adhesion and paintability associated with polyurethanes with the UV stability and weather resistance associated with silicones, which is why the same cartridge works both indoors and on exposed elevations.
For contractors across Delhi NCR and the wider Indian market, the appeal is practical. One product bonds concrete, masonry, natural stone, ceramic, timber, most metals and glass, so the storeroom does not need a different adhesive for every trade. It is isocyanate-free and low-odour, cures by reaction with atmospheric moisture, and remains permanently elastic once set, meaning the joint can absorb the differential movement and vibration that rigid adhesives crack under. As an authorised Sika distributor and applicator, Space Arc supplies it with the technical backing to match the product to the substrate and the loads involved.
The technical insight
The performance comes from the silane-terminated polymer backbone. Instead of curing through solvent loss or a two-part reaction, the polymer’s reactive silane end-groups react with moisture in the air and on the substrate, cross-linking into a tough, flexible elastomer. Because a skin forms within roughly 15 minutes and cure proceeds at about 3 mm per 24 hours at 23 degrees C and 50 percent relative humidity, the freshly applied bead is thick and cohesive enough to resist slump the instant the element is pressed on. That high wet-strength or green grab is the property doing the real work on site. Once fully cured the adhesive reaches a tensile strength of around 2.2 N/mm squared with tensile strain at break near 350 percent, so the bond line stays intact while flexing under thermal cycling, wind load and vibration rather than transferring stress into the substrate. A Shore A hardness of about 50 keeps the cured line firm but never brittle across a service range of minus 40 to plus 80 degrees C.
Where it is used
- Mounting heavy facade panels, cladding trims and cornices without drilled mechanical fixings
- Bonding mirrors and glass panels to walls, both interior and in protected exterior locations
- Fixing natural stone, ceramic and terracotta elements onto concrete and masonry
- Installing metal profiles, skirtings, thresholds and architectural fixtures
- Adhering signage, letters and display elements to building facades without visible fasteners
- Bonding timber battens, sills and trims where nailing is impractical or unsightly
- Elastic bonding of dissimilar materials subject to thermal or vibration movement
- General heavy-duty interior and exterior fixing and repair work
Key advantages
- Very high initial grab holds heavy elements immediately, often removing the need for temporary props or clamps
- Bonds an exceptionally wide range of substrates, so one product covers most site fixing tasks
- Silane-terminated polymer hybrid combines PU-grade adhesion with silicone-grade UV and weather resistance
- Suitable for both interior and exterior use, including exposed facade applications
- Isocyanate-free and low-odour, making it more comfortable to work with in occupied and enclosed spaces
- Remains permanently elastic, absorbing movement and vibration instead of cracking
- Overpaintable and available in white, concrete grey and black to suit finishes
- CE-marked and backed by Sika’s documented technical data
Limitations & considerations
- It is an adhesive with sealing ability, not a dedicated movement-joint sealant for large cyclic joints
- Cure is moisture-driven, so thick sections in cold or dry conditions set more slowly than the nominal 3 mm per 24 hours
- Ambient and substrate temperature must be between +5 and +40 degrees C during application
- Surfaces must be clean, sound and adequately prepared; it will not compensate for dust, loose material or contamination
- Not intended for permanent water immersion or as a structural glazing sealant
- On difficult or non-porous substrates an adhesion test or primer may be needed before full application
Selection & best practice
Work within the +5 to +40 degrees C window and make sure both surfaces are clean, dry, sound and free of dust, grease and loose particles. On dense or coated substrates, run a small adhesion trial first and prime if required. Apply as spaced dabs roughly 30 mm across for lighter items, or as continuous vertical beads to allow trapped air and moisture to reach the adhesive on non-porous faces such as glass and metal. Press the element firmly into place within the open time so the skin has not yet formed, correcting the position immediately since grab builds fast. Support unusually heavy or top-heavy items until the adhesive has cured through, allowing for slower cure in cold or dry weather. As a guide, one 290 ml cartridge gives about 100 spots of 30 mm diameter by 4 mm, or roughly 5 m of bead from a 5 mm nozzle; heavy objects can need up to about 120 ml per linear metre. Tool and clean up while the adhesive is fresh.
Specifications
| Chemical base | Silane-terminated polymer (STP hybrid), 1-part |
| Cure mechanism | Moisture-curing |
| Density | ~1.40 kg/l (ISO 1183-1) |
| Skin time | ~15 minutes (23 C, 50% RH) |
| Cure rate | ~3 mm / 24 hours (23 C, 50% RH) |
| Tensile strength | ~2.2 N/mm² (ISO 37) |
| Tensile strain at break | ~350% (ISO 37) |
| Shore A hardness | ~50 after 28 days (ISO 868) |
| Service temperature | -40 C to +80 C |
Industry use cases
Facade and Cladding
Fixing stone, ceramic and metal facade elements onto concrete and masonry without drilled anchors, keeping elevations clean and speeding installation.
Interior Fit-Out
Bonding mirrors, glass panels, skirtings and decorative trims in hotels, retail and offices where visible fixings are unacceptable.
Signage and Branding
Mounting letters, plates and display elements to building faces with an invisible, weather-durable bond that resists UV and thermal movement.
Repair and Maintenance
Re-fixing loose stone, tiles, thresholds and architectural fixtures on existing structures where re-drilling is undesirable.
MEP and Fixtures
Securing metal profiles, brackets and fittings to mixed substrates where elastic, vibration-tolerant bonding is preferred over rigid fixings.
Frequently asked questions
What makes Sikaflex-118 Extreme Grab different from a normal adhesive sealant?
Which substrates can it bond?
Can I use it outdoors on facades?
How long does it take to cure?
How much will one cartridge cover?
Is it safe to use in enclosed or occupied spaces?
How we position Sika Sikaflex-118 Extreme Grab
Sikaflex-118 Extreme Grab is the go-to when the priority is holding a heavy element in place instantly on almost any substrate. Where the job is really about sealing a moving joint rather than bonding, look at Sika’s dedicated sealant range such as Sikaflex-11 FC+ or Sikaflex Construction+ for general construction joints. For heavy-duty elastic bonding and sealing on demanding exterior joints, Sikaflex-521 UV or the Sikaflex PRO family are worth specifying. Within our wider portfolio, Fosroc’s Nitoseal MS600 offers a comparable MS-polymer hybrid where a joint sealant is the true need, and for rigid structural bonding of concrete or steel we would point you to epoxy systems such as Fosroc Nitobond EP rather than an elastic adhesive. Space Arc can match the right product to your substrate, loads and exposure.
Fosroc Nitoseal MS600 — Choose the Fosroc MS-polymer when the job is really a moving construction joint that needs a dedicated sealant with adhesion, rather than instant high-grab bonding of heavy elements.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.