Sika Sikaswell S-2
Sika Sikaswell S-2
SikaSwell® S-2 is a 1-part polyurethane hydrophilic sealant that swells on contact with water to seal construction joints and penetrations in concrete structures, preventing water ingress. Also used as adhesive for SikaSwell® A and P swelling profiles. Available in 600 ml unipacs (20 per box). Supplied by Wahhing Waterproofing Materials.
SikaSwell® S-2 — Hydrophilic Swellable Joint Sealant
SikaSwell® S-2 is a 1-part polyurethane hydrophilic sealant which swells in contact with water to seal all types of construction joints and penetrations in concrete structures, preventing water transmission through joints. Moisture-curing, it can be used as a stand-alone joint sealing solution or as an adhesive to fix SikaSwell® A and SikaSwell® P swelling profiles. In an ideal concrete structure, the material can develop a swelling pressure of over 10 bar.
Key Features
- 1-part, easy and fast to apply
- Highly economical joint sealing solution
- Versatile solution for joints and details
- Optimised expansion rate
- Permanently water resistant (wet and dry cycles)
- Good adhesion to various substrates
- BBA system approvals with SikaSwell® A-2010
- Conforms to LEED v2009 IEQc 4.1 (VOC content < 420 g/l less water)
Applications
Joint Sealing:
- Construction joints
- Pipe and steel work penetrations through walls and floor slabs
- Around all types of penetrations and construction joints
- Construction joints in cable ducts
Fixing / Adhering Swellable Profiles:
- SikaSwell® A Profiles
- SikaSwell® P Profiles
Why Choose SikaSwell S-2?
- Active Swelling: Swells on contact with water to actively fill gaps and seal joints, developing swelling pressure of over 10 bar
- Wet-Dry Cycle Durable: Shrinks to original dimensions when dry, re-expands on further water contact for long-term performance
- Easy Application: 1-part gun-applied paste, no mixing required
- Dual Function: Works as stand-alone joint sealant or as adhesive for swelling profiles
- Internationally Certified: BBA certified, WISSBAU sealing test, Hong Kong water permeability test report
Packaging
| Type | Size |
|---|---|
| Unipac | 600 ml |
| Per box | 20 unipacs |
Technical Specifications
| Property | Value | Standard |
|---|---|---|
| Chemical Base | 1-part polyurethane, moisture curing | — |
| Appearance / Colour | Oxide red | — |
| Density | 1.24 kg/l at +23°C | ISO 2811 |
| Shore A Hardness (unswollen) | 30–50 (7 days, +23°C / 50% r.h.) | EN ISO 868 |
| Swelling Pressure | > 10 bar in ideal concrete structure | — |
| Service Temperature | -20°C to +50°C | — |
| Application Temperature (product / air / substrate) | +5°C to +35°C | — |
| Skin Time | 60 minutes (+23°C / 50% r.h.) | EN 15651-1 |
| Sag Flow | < 2 mm (+23°C / 50% r.h.) | ISO 7390 |
| Shelf Life | 9 months (unopened) | — |
Swelling Rate (Change of Volume)
| Time | Demineralised Water | 5% Saline Solution |
|---|---|---|
| 1 day | ~25% | ~8% |
| 7 days | ~100% | ~25% |
| 30 days | ~200% | ~50% |
Note: In a totally dry state, the product shrinks to its original dimensions and expands again upon further contact with water. (EN 14498)
Consumption
| Triangular Section Size | Length per 600 ml Unipac |
|---|---|
| 12 mm | 8.2 m |
| 15 mm | 6.2 m |
| 20 mm | 3.6 m |
Consumption depends on substrate roughness and absorbency. Figures are theoretical — apply to a test area first.
Recommended Triangular Section Size (Stand-Alone Use)
| Structure Thickness | Triangular Section Size |
|---|---|
| < 20 cm | 12 mm |
| 20–30 cm | 15 mm |
| 30–50 cm | 20 mm |
Curing Rate
| Time (+23°C / 50% r.h.) | Curing Depth |
|---|---|
| 1 day | ~2.0 mm |
| 10 days | ~10.0 mm |
Important Notes
- Do NOT use for movement joints — SikaSwell S-2 is for construction joints only
- Recommended for sealing against water pressures up to 2 bar; for higher pressures, use alternative Sika joint sealing solutions or contact Sika Technical Services
- Minimum concrete cover: 8 cm on both sides (reinforced concrete) or 15 cm on both sides (unreinforced concrete)
- Product must be placed in the centre of the concrete structure
- Allow SikaSwell S-2 to harden for minimum 12 hours before placing concrete; for pouring height > 50 cm, harden for at least 24 hours
- During concrete placement, compact fresh concrete well around the SikaSwell® to ensure dense concrete without voids or honeycombs
- Protect SikaSwell S-2 against water (e.g. rain) until concrete is placed
- Substrate must be sound, clean, dry or matt damp — do not apply in construction joints with standing water
- Rough surfaces must first be levelled with appropriate Sika levelling mortar or treated mechanically
- When used with SikaSwell® profiles, press profiles firmly into fresh SikaSwell S-2 within a maximum of 30 minutes
- Clean tools immediately with Sika® Colma Cleaner — hardened material can only be removed mechanically
- Store in original sealed packaging in dry conditions, protected from direct sunlight and frost
FAQ
What is SikaSwell S-2 and how is it different from regular sealant?
SikaSwell S-2 is a hydrophilic swelling sealant specifically designed for waterproofing construction joints in concrete structures. Unlike regular elastic sealants, it actively swells on contact with water (up to ~200% volume increase in demineralised water at 30 days), filling gaps and sealing joints to prevent water ingress. When dry, it shrinks back to its original size and re-expands upon future water contact. It is NOT suitable for movement joints, window/door sealing, or facade joints.
What water pressure can SikaSwell S-2 withstand?
In an ideal concrete structure, SikaSwell S-2 can develop a swelling pressure of over 10 bar. However, the manufacturer recommends it for water pressures up to 2 bar. For pressures exceeding 2 bar, alternative or supplementary Sika joint sealing solutions should be used.
How do I apply SikaSwell S-2?
Apply SikaSwell S-2 using a gun in a triangular bead onto the prepared substrate (use a triangular nozzle or cut nozzle). Select the triangular section size (12–20 mm) based on structure thickness. Allow minimum 12 hours hardening before pouring concrete (24 hours if pour height exceeds 50 cm). Protect from rain until concrete is placed.
What packaging is available?
SikaSwell S-2 is available in 600 ml unipacs, 20 per box. Contact us via WhatsApp for pricing, Mong Kok store pickup, and Hong Kong delivery.
