Mapei Super Flexible S1 Tile Adhesive 20kg – Grey & White

Mapei Super Flexible S1 Tile Adhesive 20 kg – Grey & White

Ever struggled with adhesives that skin over too quickly, slump on vertical faces, or crack under thermal stress? Mapei Super Flexible S1 solves these issues with a true S1-class deformable formula that grips instantly yet remains workable for up to 8 hours—unlike standard C1 adhesives that offer little adjustment time and can fail under movement.

Its non-slip, high-grab properties eliminate the need for battens even on large tiles, while its ability to flex up to 2.5 mm reduces the risk of grout cracking and tile detachment in service.

Built to perform in the harshest conditions, Super Flexible S1 resists frost, UV-driven ageing and chemical attack, making it perfect for interior and exterior use—from bathroom walls and kitchen floors to pool surrounds and rooftop terraces. With an open time of 30 minutes and a generous tile-adjustment window of 60 minutes, you’ll achieve uniform joints even on complex layouts. Coverage ranges from 2–5 kg/m² depending on tile size, meaning a single 20 kg bag can cover up to 5 m² of 300 × 300 mm tiles, all at bed depths up to 15 mm for fast, single-coat applications.

Features & benefits of Mapei Super Flexible S1 Tile Adhesive

• Conforms to UKCA & CE EN 12004 C2TE S1 for guaranteed flexible, high-performance adhesion across walls and floors.
• Extended pot life up to 8 hours and open time of 30 minutes, with a 60-minute tile-adjustment window to suit large-area work.
• Exceptional non-slip, high-grab, S1-flexible formulation prevents tile movement and accommodates substrate movement.
• Industry-leading resistance to frost, weathering and ageing—ideal for swimming pools, balconies & exterior terraces.
• Covers up to 5 m² per 20 kg bag (300 × 300 mm tile), with bed depths up to 15 mm for rapid, single-coat installation.

Mapei Super Flexible S1 Tile Adhesive is suitable for:

Mapei Super Flexible S1 Tile Adhesive is not suitable for: the installation of synthetic stone or natural stone that is prone to staining or floor boards (including chipboard).

Substrate preparation – floors:
Prior to applying Mapei Super Flexible S1 Tile Adhesive on concrete substrates, they must be at least 6 weeks old. Cement:sand screeds must be at least 3 weeks old. Calcium sulphate screeds must be abraded to remove the surface laitance prior to priming with Mapei Plaster Primer or Mapei Primer G Primer. They must additionally be dry to 0.5% w/w moisture when measured using a carbide hygrometer.

Ensure that floor substrates are suitably flat and level (unless a slope is required) and that walls are flush and plumb. In addition the substrate must be firm, sound, free from cracks, suitably strong to take the weight of the tiling and dry. It should also be free from any contamination likely to impair adhesion such as loose or friable areas, dust, paint, grease, wax, mould, plaster droppings etc.

As an alternative to plywood when overlaying a timber base, a minimum of 10 mm of a suitable moisture stable board e.g. cement-based tilebacker board, can be used. Where plywood is fixed directly to joists it must be a minimum of 15 mm and also screw fixed at 300 mm centres – use Mapei Stone & Porcelain Rapid Set mixed with Mapei Flexible Additive for this application.

When installing electric undertile heating cables, it is recommended that the cables are covered with a suitable levelling compound to provide a void-free and flat even base prior to using Mapei Super Flexible S1 Tile Adhesive. It is possible to cover the cables with adhesive but proceed with caution to avoid damaging the cables.

Hot water piped underfloor heating systems must be commissioned prior to the installation of tiles using Mapei Super Flexible S1 Tile Adhesive.

Cement:sand screeds should be allowed to cure for a minimum of 3 weeks after which the heating should be switched on and the temperature raised until the operating temperature is reached. This temperature should be maintained for at least 3 days before allowing to cool to room temperature. In cold conditions maintain a surface temperature of +15ºC when tiling. Allow a further 10 days after completion of tiling before switching the heating on at a rate of +5ºC per day.

When fixing to balconies with Mapei Super Flexible S1 Tile Adhesive use a suitable waterproof membrane prior to tiling. Mapei Super Flexible S1 Tile Adhesive is not suitable for fixing to roofing felt, roofing grade asphalt or bituminous systems.

Substrate preparation – walls:

Plaster substrates should be allowed to dry out for a minimum of 4 weeks prior to priming with Mapei Plaster Primer or Mapei Primer G Primer (1 week for plaster skim coats over plasterboard) and cement:sand renders for a minimum period of 2 weeks. Shiny plaster walls may require a light sanding followed by a primer coat of Mapei Plaster Primer or Mapei Primer G once all dust has been removed.

Note:

• The maximum weight of tiling onto plaster with Mapei Super Flexible S1 Tile Adhesive should not exceed 20 kg/m² or 32 kg/m² for plasterboard (not skimmed). Plasterboard and other construction boards must be well secured and rigid. Painted surfaces must be firmly bonded to the wall substrate ensuring that all loose and flaking areas are thoroughly removed.
• When tiling to painted substrates with Mapei Super Flexible S1 Tile Adhesive the success of the installation relies on the strength of the paint bond to the wall. In cases of doubt remove the paint finish or carry out a small trial area. Very porous surfaces may be primed with Mapei Plaster Primer or Mapei Primer G to reduce the suction.
• In shower areas protect the substrate with a suitable waterproof coating prior to fixing the tiles with Mapei Super Flexible S1 Tile Adhesive. Do not use bitumen based waterproof coatings / membranes.

Product Preparation:

Place between 5.4-5.8 litres for white and 4.8-5.2 litres for grey of clean water into a clean mixing bucket. Slowly add the Mapei Super Flexible S1 Tile Adhesive powder from a 20 kg bag whilst continuously stirring with a mechanical mixer set to a slow speed. Mix for approx. 2-3 minutes until the mix is free from lumps. Where smaller quantities are to be mixed, use between 0.27 and 0.29 litres per 1 kg of powder (approx. 1 part water to 3.5 parts powder).

Product Application:

Spread Mapei Super Flexible S1 Tile Adhesive onto the correctly prepared substrate using a suitable notched trowel ensuring that a minimum of 65% coverage is achieved in dry interior wall areas with 100% in wet areas, on floors and all exterior areas.

Mapei Super Flexible S1 Tile Adhesive has excellent resistance to tile slip so usually battens are not required when fixing. Remove tiles occasionally to check the contact area. To ensure that the substrate is sufficiently wetted out by the adhesive and to close-off open textured screeds etc. it is recommended that a thin skim coat of Mapei Super Flexible S1 Tile Adhesive is spread over the background using the flat side of the trowel prior to combing more adhesive onto the area.
Press the tiles in position, before the adhesive has formed a skin, using a twisting action to ensure good adhesive contact. Leave clean open joints between the tiles. Do not spread more adhesive than can be tiled within 30 minutes and do not apply when the temperature is less than +5ºC or above +30°C.

Use Mapei Super Flexible S1 Tile Adhesive in white when installing lighter coloured stone. Always check compatibilty between stone and adhesive in a small trial area before proceeding.

Consumption:

Dependent on the size of the tile and the type of installation – between 2 and 5 kg/m². When using a typical 300×300 mm tile on a flat even base, a 20 kg bag may cover up to 5 m².