
Keraflex Maxi S1
High-performance, deformable cementitious adhesive, grey or ultra white, with no vertical slip, extended open time and Low Dust technology, especially suitable for large-size porcelain tiles and natural stone.
Supplied by SARP & LAB, the only authorised MAPEI distributor in Albania.
Where it is used
- All types and sizes of ceramic tile on exterior and interior walls and floors, on uneven substrates and plaster, up to 15 mm thick
- Dimensionally stable stone not susceptible to moisture or staining, indoors and outdoors
- Mosaics of all types, indoors and outdoors, including in swimming pools
- Cementitious and anhydrite screeds, underfloor heating, stable cured concrete floors, precast concrete walls and rigidly supported plasterboard
- Waterproofing membranes in Mapelastic, Mapelastic Smart, Mapelastic Turbo, Mapelastic AquaDefense or Mapegum WPS
- Flooring subject to heavy footfall, and indoor overlays on existing well-bonded, crack-free floors of ceramic, terrazzo and stone
Why Keraflex Maxi S1
- No sinking of heavy, large tiles on floors and no vertical slip on walls
- Low Dust technology: low dust emission during mixing
- Class S1: transversal deformability over 2.5 mm, measured to EN 12004
- Extended open time
- EC1 Plus: very low emission of volatile organic compounds
- Residual greenhouse gas emissions offset for the year 2026; EPD-certified life cycle
How it is applied
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Prepare the substrate
It must be cured, sufficiently dry, strong and free of crumbling areas, grease, oil, varnish or 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, Mapecem Pronto, Topcem or Topcem Pronto. Gypsum and anhydrite must be perfectly dry (max. residual humidity 0.5%, 0.3% for heated screeds) and treated with an acrylic primer such as Primer G or Eco Prim T Plus.
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Mix
Blend with clean water, 28-30 parts per 100 parts by weight: approximately 7-7.5 litres per 25 kg bag of grey, 6.5-7 litres per 23 kg of white. Let it stand for approximately 5 minutes and blend again.
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Spread
Apply a thin layer with the smooth side of the spreader, then immediately a further layer to the required thickness. Dampen very absorbent substrates in high temperatures to prolong 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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Bond and protect
Tiles do not need wetting; dip very dusty backs in clean water. Press down firmly. If the adhesive is no longer wet, run the notched trowel over it 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 4-8 hours on walls and after 24 hours on floors with MAPEI cementitious or epoxy grouts. Seal expansion joints with MAPEI sealants.
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 by weight of grey or white with 28-30 parts by weight of water |
| Pot life of mix | more than 8 hours |
| Application temperature | +5°C to +35°C |
| Open time | over 30 minutes |
| Adjustment time | approximately 45 minutes |
| Grouting | walls after 4-8 hours · floors after 24 hours |
| Set to foot traffic | 24 hours |
| Ready for service | 14 days; basins and swimming pools may be filled after 21 days |
| Adhesion: initial (after 28 days) · after heat · after water · after freeze-thaw | 2.6 · 2.5 · 1.1 · 1.3 N/mm² |
| Consumption | 1.2 kg/m² per mm of thickness |
| Packaging | grey 25 kg, white 23 kg, in paper bags |
| Storage | 12 months in original packaging, in a dry place |
Source: MAPEI technical data sheet 56-9-2026; typical values. Check the current data sheet before use. Product page at MAPEI
Application precautions
- Do not use on concrete that has not been adequately cured
- Do not use on wood and wood-based composites, or on metal, rubber, PVC or linoleum surfaces
- Not on marble slabs, natural stone or reconstituted materials prone to efflorescence, staining or movement caused by moisture
- Not on floors and wall coverings subject to significant movement or vibration
- Not where the surface must be ready for foot traffic quickly
- Do not add water to the mix once it starts to set
Product for professional use.
Our projects with Keraflex Maxi S1
Used together with
Frequently asked questions
How much do I need per m²?
Consumption is 1.2 kg/m² per mm of thickness. For example, a 5 mm layer uses about 6 kg/m², so a 25 kg bag covers approximately 4 m² at that thickness.
Is it suitable for large tiles and natural stone?
Yes, it is especially suitable for large-size porcelain tiles and for natural stone, provided the stone is dimensionally stable and not susceptible to moisture or staining.
Can it go over a waterproofing membrane?
Yes, over Mapelastic, Mapelastic Smart, Mapelastic Turbo, Mapelastic AquaDefense or Mapegum WPS.
Can it go over existing floors?
Yes, indoors, on existing floors of ceramic tiles, terrazzo and stone, provided they are adequately bonded to the substrate and free from cracks.
When can the floor be used?
Floors take foot traffic after approximately 24 hours. Surfaces may be put into service after 14 days, and basins and swimming pools 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.


