Sika SikaBond AT Universal
A silicone-free, solvent-free silane-terminated polymer that bonds and seals in one pass, staying flexible from -40 C to +80 C without a primer on most building substrates.
What is it?
A one-component, moisture-curing elastic adhesive and sealant based on silane-terminated polymer (STP/MS hybrid) chemistry, supplied in 300 ml cartridges and 600 ml foil packs.
Where is it used?
Interior and exterior bonding of cladding, cover plates, cable channels, acoustic panels, door sills, skirtings and lightweight elements, plus low-movement sealing joints.
Why use it?
It bonds a very wide range of porous and non-porous substrates without a primer, cures to a tough yet flexible film, and is silicone-free so it can be over-painted.
How is it applied?
Gun-applied as a bead or dabs from a cartridge or foil pack onto a clean, sound surface, then the parts are positioned within the open time and left to cure by ambient humidity.
About Sika SikaBond AT Universal
SikaBond AT Universal is Sika’s workhorse elastic bonding adhesive for the kind of everyday fixing jobs that a builder, fabricator or fit-out contractor faces on almost every site. It replaces mechanical fasteners in situations where drilling is undesirable, distributes stress across the whole bonded area rather than concentrating it at fixing points, and accommodates the small differential movements that occur when dissimilar materials expand and contract at different rates. Because it is a single-component product that cures on contact with atmospheric moisture, there is no mixing, no pot life to watch and no wastage of a part-used pack. The same bead can act as both a structural-grade adhesive and a weatherproofing seal, which is why it has become a standard item in the toolbox for facade work, interior fit-outs and general assembly. It is important to correct a common misconception, including one that appeared on our own older listing: this grade is not a polyurethane. The current Sika technical data sheet confirms it is built on silane-terminated polymer chemistry, the same family marketed elsewhere as MS or hybrid technology. That distinction matters on site because the STP backbone is silicone-free and solvent-free, which means the cured bead can be over-painted, will not bleed oils that stain porous stone, and carries none of the isocyanate labelling associated with older polyurethane adhesives. For engineers and specifiers in India who are matching a written specification against what actually arrives on site, getting the chemistry right avoids compatibility surprises with adjacent coatings and sealants.
The technical insight
The performance comes from the silane-terminated polymer backbone. When the bead is exposed to atmospheric moisture, the reactive silane end-groups hydrolyse and then condense together, cross-linking the liquid paste into a firm elastic solid and forming stable siloxane bonds to the substrate surface. That surface reaction is what allows the product to grip both non-porous materials such as glass, metal, ceramics and many plastics, and porous materials such as concrete, render and timber, without the primer step a polyurethane usually needs. Curing advances from the surface inward at roughly 3 mm per 24 hours at 23 C and 50 percent relative humidity, so thicker beads and confined joints simply take longer to reach full strength. After 28 days the cured adhesive reaches around 33 Shore A hardness with a tensile strength near 1.5 N/mm2, giving a bond that is firm enough to carry load yet elastic enough to absorb differential movement of about plus or minus 20 percent. Because the reaction consumes ambient humidity rather than releasing solvent, there is minimal shrinkage and the film stays dimensionally honest to the bead you laid down.
Where it is used
- Elastic bonding of interior and exterior cladding panels, cover plates and trims
- Fixing cable channels, conduits and cable trays to walls and soffits
- Bonding acoustic tiles, insulation boards and lightweight construction elements
- Installing door sills, thresholds, skirtings and window boards
- Adhering roof and wall coverings where mechanical fixings are undesirable
- Sealing and bonding around metal and ceramic components in fit-out work
- Low-movement weatherproofing and connection joints as a secondary sealant role
- General workshop and prefabrication assembly of dissimilar materials
Key advantages
- Single component, moisture-curing, so no mixing and no pot-life management on site
- Bonds most porous and non-porous substrates without a separate primer
- Silicone-free and over-paintable, unlike traditional silicone sealants
- Solvent-free and isocyanate-free STP chemistry with a low odour on site
- Stays elastic across a wide service range of -40 C to +80 C after cure
- Accommodates around plus or minus 20 percent joint or bond-line movement
- Available in white and dark-grey, in 300 ml cartridges and 600 ml foil packs
- Good gunnability and non-slump paste that holds a vertical bead
Limitations & considerations
- It is an elastic adhesive-sealant, not a structural glazing or engineered structural adhesive; load-bearing bonds must be validated by the design engineer
- Cure is moisture and temperature dependent and slows markedly in cold, dry conditions, curing at roughly 3 mm per 24 hours
- Not resistant to alcohols, organic acids, concentrated acids or alkalis, or chlorinated and aromatic hydrocarbons
- Substrates must be clean, dry and sound; it will not bond reliably over grease, laitance or friable surfaces
- Movement capability of about plus or minus 20 percent makes it unsuitable for high-movement expansion joints that need a dedicated joint sealant
- Application and substrate temperature should stay within +5 C to +40 C for correct cure
Selection & best practice
Prepare every substrate first: it must be clean, dry, sound and free of oil, grease, dust, cement laitance and any loose or friable material, with old paint or poorly adhering coatings removed. Although the product bonds without a primer on most surfaces, run a small adhesion trial on unfamiliar or critical substrates before committing to the full job. Keep both ambient and substrate temperature within +5 C to +40 C, and keep the substrate at least 3 C above the dew point to avoid condensation spoiling the bond. Apply from a cartridge gun as continuous beads or spaced dabs, then position and press the parts firmly within the open time so the adhesive wets both faces. Support or clamp heavier elements until the bead has developed enough early strength, and remember that full strength builds over about 7 days as the cure penetrates deeper at roughly 3 mm per day. Tool sealing joints promptly, and store unused packs sealed, dry and out of direct sun between +5 C and +25 C to protect the 12-month shelf life.
Specifications
| Chemical base | Silane-terminated polymer (STP / MS hybrid), 1-component |
| Cure mechanism | Moisture-curing (reacts with atmospheric humidity) |
| Colour | White, dark-grey |
| Packaging | 300 ml cartridge (12/box); 600 ml foil pack (20/box) |
| Density | Approx. 1.40 kg/litre |
| Skin time | Approx. 35 minutes at 23 C / 50% RH |
| Curing rate | Approx. 3 mm per 24 hours at 23 C / 50% RH |
| Shore A hardness | Approx. 33 after 28 days |
| Tensile strength | Approx. 1.5 N/mm2 (28 days) |
| Movement capability | Approx. +/- 20% |
| Service temperature | -40 C to +80 C |
| Application temperature | +5 C to +40 C (ambient and substrate) |
| Shelf life | 12 months from production in sealed original packaging |
Industry use cases
Building Facades & Cladding
Elastic bonding of cover plates, trims and lightweight cladding elements where drilling fixings would damage the panel or breach the envelope, letting the bond flex with thermal movement.
Interior Fit-Out
Fixing skirtings, door sills, window boards, acoustic tiles and insulation boards to masonry or drywall without visible fasteners, then over-painting the exposed adhesive to match finishes.
MEP & Services
Adhering cable channels, conduit and trunking to walls and soffits in plant rooms and risers, avoiding drilling into sensitive or waterproofed substrates.
Prefabrication & Fabrication
Workshop assembly of dissimilar materials such as metal to composite or ceramic, where a single primerless adhesive-sealant simplifies the line and absorbs movement between components.
Frequently asked questions
Is SikaBond AT Universal a polyurethane adhesive?
Do I need a primer before bonding?
How long does it take to cure?
What pack sizes and colours are available?
Can I use it as a proper expansion joint sealant?
What is its service temperature range?
How we position Sika SikaBond AT Universal
SikaBond AT Universal sits in the middle of Sika’s elastic bonding range as the go-to primerless adhesive-sealant for everyday fixing. Where the job is a true movement joint rather than a bond, step across to the Sikaflex family of polyurethane and hybrid joint sealants, which offer higher movement accommodation. For heavy-duty structural or flooring bonds, other SikaBond grades and Sika’s epoxy adhesives are the correct specification. Within our wider catalogue, the closest cross-brand equivalent is Fosroc’s Nitoseal MS300, another MS-polymer hybrid; and for cementitious bonding rather than elastic bonding, look at epoxy and SBR bonding agents such as Fosroc Nitobond. Our team can help you match the exact grade to your substrate, movement and load requirements.
Fosroc Nitoseal MS300 — A specifier standardising on Fosroc for facade and joint work can choose Nitoseal MS300, an MS-polymer hybrid in the same silicone-free, over-paintable family, where its stronger weatherproofing-joint pedigree is preferred over SikaBond’s general bonding focus.
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