Sika Sikasil MultiPlus-T
A fast-skinning, fungus-resistant acetoxy silicone for sanitary and glazing joints in wet, humid interiors.
What is it?
A single-component, acetoxy moisture-curing silicone sealant with a built-in fungicide, engineered for sanitary and universal glazing joints.
Where is it used?
Bathrooms, kitchens, showers, washbasins, ceramic tile perimeters and glass-to-frame joints in Indian homes, hotels and commercial washrooms.
Why use it?
It seals fast, stays flexible, and resists the black mould and mildew that plague high-humidity Indian interiors.
How is it applied?
Gun-applied from a 280 ml or 120 ml cartridge into a clean, dry joint, then tooled smooth before the skin forms.
About Sika Sikasil MultiPlus-T
Sikasil MultiPlus/-T is Sika’s workhorse acetoxy silicone for the wet zones of a building, where water, steam and warmth constantly conspire to grow mould in joint lines. It is a one-part system that cures on contact with atmospheric moisture, releasing the characteristic acetic-acid smell of acetoxy chemistry as it sets. What sets it apart from a generic bathroom silicone is the fungicidal package built into the compound, which keeps the classic black staining at bay far longer in the humid conditions typical of Indian kitchens, bathrooms and coastal buildings.
For a contractor, the appeal is speed and versatility. The sealant skins over in roughly 25 minutes and cures at about 2 mm per 24 hours, so a bathroom sealed in the morning can usually be handed back into service the same day. It grips glass, glazed ceramic, vitreous china, painted surfaces and anodised aluminium without a primer, which cuts a step out of every job. Space Arc supplies it as an authorised Sika channel partner across Delhi NCR and Pan-India, with the technical backing to specify it correctly against wetter, more demanding site conditions.
The technical insight
The performance comes from the acetoxy cure system paired with a fungicidal additive. As an acetoxy silicone, MultiPlus/-T reacts with humidity in the air to crosslink into a durable elastomer, and because that reaction is fast it develops a tack-free skin quickly and reaches a Shore A hardness of around 18 after 28 days. The cured rubber stays low-modulus and elastic, with roughly 150% elongation at break and a secant tensile modulus near 0.36 N/mm2 at 100% elongation, so the joint can flex with day-night and thermal movement instead of tearing or debonding. The embedded fungicide leaches slowly to the surface over the sealant’s life, poisoning the microclimate that mould spores need to colonise the bead. That is why it holds its clean appearance in showers and around sinks long after an ordinary silicone would have gone black at the edges.
Where it is used
- Sealing the perimeter joints of bathtubs, shower trays and cubicles
- Washbasin, WC and sanitary-fixture connections to walls and floors
- Kitchen countertop, sink and splashback joints
- Perimeter sealing of ceramic and vitreous wall and floor tiles in wet areas
- Internal glazing and glass-to-frame joints in windows and partitions
- Sealing around anodised aluminium and painted joinery in interiors
- General non-structural sanitary jointing in hotels, hospitals and commercial washrooms
- Sealing cold-room and refrigerated cabinet joints where hygiene matters
Key advantages
- Built-in fungicide resists mould and mildew staining in humid conditions
- Fast skin-over of about 25 minutes speeds up finishing and turnaround
- Cures at roughly 2 mm per 24 hours so joints return to service quickly
- Adheres to glass, ceramic, vitreous, painted and anodised aluminium without primer
- Stays elastic with around 150% elongation to absorb joint movement
- Good resistance to common household and commercial cleaning agents
- Wide service range from around -40 C to +100 C once cured
- Carries EN 15651-3 classification for sanitary joints
Limitations & considerations
- Acetoxy cure releases acetic acid vapour, so it corrodes and stains unprotected metals like copper, brass, lead and mild steel
- Not suitable for porous substrates such as natural stone, marble, concrete or unglazed masonry, which it can edge-stain
- Non-structural sealant only; it is not designed for structural glazing or load-bearing bonds
- It cannot be over-painted, so it must be the final finish in the joint
- Limited colour range compared with neutral-cure ranges, restricting matching options
- Not intended for continuous water immersion, aquariums or high-movement expansion joints
Selection & best practice
Success with an acetoxy silicone is mostly about substrate preparation and joint geometry. Cut the cartridge nozzle to the bead width and gun the sealant into a joint that is clean, dry and free of dust, grease, soap film and old sealant; solvent-wipe glass and glazed surfaces first. Work between +5 C and +40 C on both the substrate and the material. For a sanitary joint, aim for a seal depth of about 6 mm on 6-12 mm wide joints, and use a bond-breaker tape or backing where the joint is deep so the bead adheres only to the two faces. Tool the bead smooth with a soapy-water spatula within the roughly 25-minute skin time to get a clean concave finish, and mask adjacent surfaces before tooling. Keep it well away from copper, brass and other sensitive metals, and never apply it over porous stone. Allow it to cure undisturbed, protecting the joint from water until it has set.
Specifications
| Chemical base | One-part acetoxy silicone, moisture-curing |
| Density | Approx. 0.98 g/cm3 |
| Skin time | Approx. 25 minutes (23 C / 50% r.h.) |
| Curing rate | Approx. 2 mm / 24 h (23 C / 50% r.h.) |
| Elongation at break | Approx. 150% |
| Shore A hardness | Approx. 18 (after 28 days) |
| Secant tensile modulus | Approx. 0.36 N/mm2 at 100% elongation (23 C) |
| Service temperature | -40 C to +100 C |
| Standard / pack | EN 15651-3 S; 280 ml and 120 ml cartridges; shelf life 18 months |
Industry use cases
Residential wet areas
Sealing bath, shower, washbasin and kitchen-sink joints in homes where mould resistance keeps the silicone line looking clean for years.
Hospitality and hotels
Fast-turnaround sanitary sealing of guest bathrooms and back-of-house kitchens where downtime per room must be minimised.
Healthcare and labs
Hygienic jointing of washrooms, sluice rooms and cleanable surfaces where fungal resistance supports infection-control standards.
Interior glazing and joinery
Primerless glass-to-frame and partition glazing joints, plus sealing around anodised aluminium and painted interior joinery.
Cold storage and food service
Sealing refrigerated cabinet and cold-room joints where hygiene and mould control are essential in humid conditions.
Frequently asked questions
Is Sikasil MultiPlus-T really mould resistant, or does it stain like ordinary silicone?
Can I use it on marble, granite or other natural stone?
Will it corrode metal fittings around the joint?
How soon can the bathroom be used after sealing?
Can the sealant be painted over to match the wall?
What pack sizes and colours does Space Arc supply?
How we position Sika Sikasil MultiPlus-T
Within the Sika family, Sikasil MultiPlus/-T is the general-purpose sanitary and glazing silicone; where a project needs neutral-cure chemistry for stone or sensitive metals, or higher-modulus performance for structural and weatherproofing glazing, Sika’s neutral silicone and high-modulus Sikasil ranges are the natural step up. For movement joints in facades, floors and general construction, where acetoxy silicone is the wrong tool, we would move the specifier onto an MS-polymer or polyurethane sealant. From our other brands, Dr. Fixit and other sanitary silicones cover comparable bath-and-kitchen jointing, while STP joint systems suit larger structural and expansion joints. Space Arc can match the chemistry to the substrate rather than defaulting to one product.
Fosroc Nitoseal MS600 — Specify the Fosroc MS-polymer sealant instead when the joint sees real movement or sits on porous or metal substrates, where an acetoxy sanitary silicone is unsuitable.
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Authorised distribution, technical advice & professional application across Delhi NCR and Pan-India.