Ultralite S1 Flex
One-component, deformable, lightweight cementitious adhesive, grey or ultra white, with no vertical slip, extended open time and Low Dust technology, for ceramic and stone tiles and ideal for large formats.
Supplied by SARP & LAB, the only authorised MAPEI distributor in Albania.
Where it is used
- All types and sizes of ceramic tile, and all types of mosaic, indoors and outdoors, also in swimming pools
- Large format porcelain tiles and thin porcelain tiles on floors, specifically on large surface areas
- Stone tiles indoors and outdoors, as long as the stone is not sensitive to moisture and staining
- Interior and exterior walls, including exterior façades
- Balconies, terraces and flat roofs subject to direct sunlight and temperature swings
- Mapelastic, Mapelastic Smart, Mapelastic Turbo, Mapelastic AquaDefense or Mapegum WPS membranes; stable marine plywood, particleboard and existing wooden floors
Why Ultralite S1 Flex
- Lighter bags: a 15 kg bag has approximately the same yield as a 25 kg bag of conventional MAPEI cementitious adhesive
- One pallet weighs 750 kg, against 1250 kg for conventional adhesive
- High back-buttering capacity limits voids between substrate and tile
- Class S1: transversal deformability over 2.5 mm, measured to EN 12004; no vertical slip
- Low Dust technology, and EC1 Plus for very low emission of volatile organic compounds
- Residual greenhouse gas emissions offset for the year 2026; certified for use in the marine industry
How it is applied
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Prepare the substrate
It must be sound, sufficiently dry and free of loose parts, grease, oil, paint and wax. In good weather, cure render for at least one week per cm of thickness and cementitious screeds for at least 28 days, unless made with Mapecem, Topcem, Mapecem Pronto or Topcem Pronto. Treat dry gypsum and anhydrite with an acrylic primer such as Primer G or Eco Prim T Plus. For thin porcelain tiles the substrate must be perfectly flat.
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Mix
Blend with clean water, approximately 7.5-7.8 litres per 15 kg bag, to a smooth, lump-free mix. Let it stand for approximately 5 minutes and blend again.
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Spread
Apply a thin layer with the flat side of the trowel, then immediately a second layer to the required thickness with a notched trowel suited to the tile. Wet very absorbent substrates in high temperatures to extend the open time.
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Back-butter where needed
For exterior installation, large format tiles, heating floors, floors to be polished after laying or under heavy loads, water tanks and swimming pools, also spread adhesive on the back of the tile. This is also recommended for thin porcelain floor tiles.
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Install and protect
Tiles do not need wetting; dip very dusty backs in clean water. Apply firm pressure. If a dry skin forms, run the notched trowel over the adhesive again, and do not wet it. Adjust within 45 minutes. Protect from water and rain for at least 24 hours, and from freezing weather and direct sunlight for at least 5 to 7 days.
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Grout and seal
Grout after 4 to 8 hours on walls and after 24 hours on floors with a MAPEI cementitious or epoxy grout. Seal expansion joints with a MAPEI sealant.
Technical data
| Classification (EN 12004, ISO 13007-1) | C2TES1 |
| Deformability (EN 12004) | S1, deformable: over 2.5 mm and under 5 mm |
| Mixing ratio | 100 parts grey or white with 50-52 parts of water by weight |
| Pot life of mix | over 8 hours |
| Application temperature | from +5°C to +40°C |
| Open time | 30 minutes |
| Adjustment time | 45 minutes |
| Grouting | walls after 4-8 hours · floors after 24 hours |
| Set to foot traffic | 24 hours |
| Ready for use | 14 days; tanks and swimming pools can be filled after 21 days |
| Bond strength: initial (after 28 days) · after heat · after water · after freeze-thaw | 1.8 · 1.8 · 1.2 · 1.5 N/mm² |
| Consumption | 0.8 kg/m² per mm of thickness: 1.5 kg/m² for uncoupling or waterproofing membranes (5 mm notched trowel), 2-3.5 kg/m² for tiles (by trowel) |
| Packaging | white and grey in 15 kg paper bags with handle |
| Storage | 12 months in original packaging, in a dry area |
Source: MAPEI technical data sheet 2895-7-2026; typical values. Check the current data sheet before use. Product page at MAPEI
Application precautions
- Do not use on concrete that has not been thoroughly cured
- Do not use on metal, rubber, PVC and linoleum substrates
- Not for slabs of marble and natural stone subject to efflorescence or staining
- Not for natural or agglomerate stone subject to moisture expansion
- Not when the floor must take foot traffic quickly
- Do not add water to the mix once it starts to set
Product for professional use.
Used together with
Frequently asked questions
How much do I need per m²?
0.8 kg/m² per mm of thickness, which is 2-3.5 kg/m² for tiles depending on the trowel. A 15 kg bag therefore covers approximately 4 to 7.5 m² of tiling.
Why is the bag only 15 kg?
The low density formula means a 15 kg bag has the same volume as, and approximately the same yield as, a 25 kg bag of conventional MAPEI cementitious adhesive.
Is it suitable for large format and thin porcelain tiles?
Yes. It is ideal for large formats, and its back-buttering properties make it particularly suitable for thin porcelain tiles, on a perfectly flat substrate.
Can it be used on balconies and terraces?
Yes, for ceramic and natural stone tiles on balconies, terraces and flat roofs subject to direct sunlight and temperature swings.
When can the floor be used?
Floors take light foot traffic after approximately 24 hours. Surfaces are ready for use after approximately 14 days, and tanks and swimming pools can be filled after 21 days.
Is there a warranty?
If required, MAPEI can provide a warranty for each product it sells. Contact us about your case.