Description
Ultralite S1 Flex Zero is a one-component, deformable, lightweight cementitious adhesive built specifically around large-format tile installation, where its high back-buttering capacity does real work limiting void formation between the substrate and the tile. That’s a genuine structural consideration — an unsupported void under a large porcelain tile is exactly where a crack starts under point loading from furniture or foot traffic.
Classified C2TES1 under AS ISO 13007.1, it carries a real compliance basis: cementitious, improved, slip-resistant, with extended open time and deformable characteristics all independently certified rather than claimed. It’s also part of Mapei’s CO2 Fully Offset line, with life-cycle emissions verified via EPDs and offset through certified carbon credits supporting forestry protection — a genuinely documented sustainability claim rather than a general eco label.
Technical Specifications
| AS ISO 13007.1 classification | C2TES1 |
|---|---|
| Pot life | Approx. 8 hours |
| Open time | At least 30 minutes (reduced on very absorbent substrates) |
| Set to light foot traffic | Approx. 24 hours |
| Ready for use | Approx. 14 days |
| Tanks/pools fillable | Minimum 21 days |
| Consumption | 0.8 kg/m² per mm thickness (2-3.5 kg/m² for tiles, trowel dependent) |
| Packaging | 13.5kg paper bags (grey) |
Where to Use
- All types and sizes of ceramic, porcelain, clinker and terracotta tiles, interior and exterior
- Mosaic, including in swimming pools
- Large-format and thin porcelain tiles on large surface areas
- Interior and exterior walls, including facades
How to Apply
- Prepare the substrate — self-levelling compounds, cured concrete, cementitious or lime-mortar render, or primed gypsum-based render.
- Mix — combine to a smooth, workable paste; pot life is approximately 8 hours.
- Apply within the open time — at least 30 minutes, less on very absorbent substrates; wetting the substrate first can extend this.
- Back-butter large tiles — apply adhesive to the tile back as well as the substrate to limit voids.
- Allow to set — light foot traffic after 24 hours, full use after 14 days.
Important Notes
- Tanks and swimming pools need a minimum 21-day cure before filling.
- Clean tools and containers with water while the adhesive is still fresh.
- For professional use only.
< That void-limiting performance is really what the C2TES1 classification is certifying in practice — a real, tested outcome rather than a generic adhesive claim. Its extended open time also gives real practical benefit on a large-format tiling job, where each individual tile simply takes longer to position and level correctly than a smaller standard tile would. Checking the substrate's actual porosity before committing to a fixed open time expectation is worth the extra minute, since a highly absorbent substrate can shorten that working window meaningfully compared with the standard 30-minute figure.
Large-format tiles have become significantly more common in both commercial and residential specification over recent years, and that trend is exactly what’s driving adhesive formulations like Ultralite S1 Flex Zero — a standard-yield, standard-open-time adhesive designed around smaller tile formats genuinely struggles to keep pace with an installer working across a big single porcelain slab, both in terms of coverage per bag and the time available before the adhesive skins over.
