Palace Multi-Flex S1 Flexible Tile Adhesive Grey 20kg
Multi-Flex S1 Flexible Tile Adhesive Grey 20kg is a professional-quality, rapid-setting cement-based adhesive designed for demanding wall and floor tiling projects. Its flexible, fibre-reinforced formulation provides excellent bond strength and dependable performance across a wide range of properly prepared substrates. Suitable for both interior and exterior applications, this versatile adhesive can be used when fixing ceramic, porcelain, mosaic, marble and many types of natural stone tile.
Classified as C2FTE-S1 under BS EN 12004, Multi-Flex provides improved adhesion, rapid setting, reduced slip, extended open time and deformable performance. These characteristics make it particularly useful for projects involving large-format tiles, heated floors or substrates that may experience limited movement. The adhesive’s strong initial grab helps keep tiles securely positioned during installation, while its workable consistency makes spreading and bedding easier.
Suitable for a Wide Range of Tiles
Multi-Flex S1 Grey is suitable for installing many commonly used wall and floor coverings, including ceramic tiles, fully vitrified porcelain, mosaics, marble and natural stone. Its strong bond makes it an excellent option for porcelain tiles, which typically require a high-performance adhesive due to their low porosity.
The product is available in grey and white formulations. When installing light-coloured or translucent marble, travertine or other potentially sensitive natural stone, the white version should be used to reduce the risk of the adhesive colour showing through or affecting the appearance of the finished surface. Always confirm the suitability of the adhesive for the chosen tile before starting the full installation.
Interior and Exterior Applications
This flexible tile adhesive can be used on properly prepared walls and floors in both indoor and outdoor locations. Typical applications include kitchens, bathrooms, showers, utility rooms, entrance areas and general living spaces. It is also suitable for wet areas and swimming pools when the supporting background and waterproofing system have been correctly designed and prepared.
Multi-Flex S1 can be applied to substrates such as cured concrete, cement-based screeds, suitable renders, tile backer boards and other stable building surfaces. It may also be used over suitably prepared existing tiles and power-floated concrete. Smooth, dense or impermeable surfaces must be thoroughly cleaned and prepared to create a sound key before the adhesive is applied.
Compatible with Underfloor Heating
The S1 flexible classification makes this adhesive suitable for appropriately prepared underfloor heating installations. Its deformable properties help accommodate the limited thermal movement produced as a tiled floor heats and cools. The heating system must be switched off before installation, and the substrate should be allowed to return to a suitable working temperature.
After tiling, allow the completed installation to cure for at least 28 days before switching the underfloor heating back on. The temperature should then be increased gradually during the first week rather than being brought immediately to full operating temperature. Always follow the instructions supplied by the heating-system and tile manufacturers.
Rapid Setting and Practical Working Time
Once mixed, Multi-Flex S1 has an approximate working pot life of 40–60 minutes, depending on temperature and site conditions. Only mix as much adhesive as can be comfortably applied during this period. Spread the adhesive using a suitably sized notched trowel and fix the tiles before a skin forms, normally within approximately 30–40 minutes.
The adhesive begins its initial set after approximately two hours at 20°C and can normally be ready for grouting after around three to four hours. Lower temperatures, dense tiles, impermeable backgrounds and thicker adhesive beds can extend these times. Do not attempt to restore workability by adding extra water after the adhesive has started to set.
Mixing and Application
Use clean water and clean mixing equipment. Add approximately 4.4–4.8 litres of water to a clean container for each 20kg bag, then gradually add the powder while mixing with a slow-speed electric paddle. Continue mixing until a smooth, lump-free consistency is achieved. Avoid adding more water than recommended, as this may reduce strength and alter the adhesive’s performance.
Apply the mixed adhesive to the prepared surface and comb it in one direction with the appropriate notched trowel. Press each tile firmly into place with a slight twisting or sliding action to collapse the adhesive ribs. Periodically lift a tile to confirm adequate contact. Floors, exterior areas, wet locations and large-format tiles generally require complete adhesive coverage with no significant voids beneath the tile.
The adhesive can be applied at depths of up to approximately 16mm where required. Do not use excessive thickness to correct major irregularities in the background; uneven surfaces should be repaired or levelled with a suitable preparation product before tiling.
Surface Preparation
All backgrounds must be structurally sound, stable, clean and free from dust, laitance, oil, grease, curing compounds, loose paint and other contaminants that could reduce adhesion. New concrete should generally be allowed to cure for at least four weeks before tiling. Worn or porous concrete may require priming with Palace Multi-Prime diluted according to the manufacturer’s instructions.
Bare gypsum and anhydrite surfaces require suitable priming before cement-based adhesive is applied. Timber floors must be rigid, adequately braced and prepared using an appropriate tile backer-board system. Multi-Flex should not be applied directly to tongue-and-groove floorboards, unstable timber or floating floor systems.
Coverage
Coverage depends on the tile size, trowel notch, background condition and required bed thickness. As a general guide, a 20kg bag may cover approximately 5m² on floors when used at about 4kg per square metre. Wall applications may achieve around 8m² when used at approximately 2.5kg per square metre. Uneven substrates, large-format tiles and back-buttering will increase consumption.
Key Benefits
- Rapid-setting, cement-based tile adhesive
- Flexible and fibre-reinforced S1 formulation
- High bond strength and strong initial grab
- Reduced-slip properties for wall applications
- Suitable for ceramic, porcelain, mosaic and natural stone tiles
- Can be used with large-format tiles
- Suitable for interior and exterior walls and floors
- Compatible with properly installed underfloor heating
- Suitable for wet areas and swimming pools
- Can be applied at depths of up to approximately 16mm
- Approximately 40–60 minutes’ working pot life
- Normally ready for grouting after approximately three to four hours
Storage and Safety
Store the unopened bag in a cool, dry location, raised clear of the ground and protected from moisture. The product contains cement and produces an alkaline reaction when mixed with water. Avoid breathing dust and prevent contact with the eyes or prolonged contact with skin. Wear suitable gloves, protective clothing and eye protection while mixing and applying the adhesive. Always consult the latest manufacturer’s technical and safety data sheets before use.
