Mapei Ultralite S2

Mapei Ultralite S2 is a single pack, high-performance, highly-deformable, lightweight cementitious adhesive with extended open time and very high yield, easy to trowel and good buttering capacity with very low emission of volatile organic compounds, for ceramic, porcelain and natural stone tiles and mosaics. Ideal for thin porcelain tiles.

Best Uses

Mapei Ultralite S2 is ideal for:

• Bonding all types and sizes of ceramic tiles (double-fired, single-fired, porcelain, klinker, terracotta, etc.) on internal and external substrates
• Bonding stone on internal and external surfaces (only stone which is stable and not sensitive to humidity)
• Bonding all types and sizes of thin porcelain tiles on floors and walls, including external façades
• Bonding all types of mosaic on internal and external substrates, even in swimming-pools
• Bonding standard ceramic and porcelain tiles directly over cable undertile heating systems
• Bonding tiles to waterproofing membranes made with Mapelastic, Mapelastic Smart, Mapelastic AquaDefense and Mapegum WPS
• Laying ceramic and stone tiles to existing tiled floors (in ceramic, marble, etc.)
• Laying on exterior grade plywood, P5 grade chipboard and old, stable wooden floors
• Laying ceramic and stone on balconies, terraces and patios exposed to direct sunlight and thermal gradients
• Bonding to precast concrete walls and concrete substrates

Mapei Ultralite S2 is specifically developed for large-sized tiles to be laid on large surface areas without double buttering. Because of its high buttering capacity on the backs of tiles, it is particularly suitable for laying any type of thin porcelain tile (using the double buttering technique).

Ultralite S2 is a grey or white powder adhesive made from cement, selected graded sand, a high amount of synthetic resin and micro-spheres of recycled silica material which helps to make the mix lighter, according to a special formula developed in MAPEI’s Research Laboratories, to offer a valid contribution towards the development of sustainable buildings.

Application

Preparation of the substrate
Substrates must be mechanically strong, free of loose parts, grease, oil, paintwork, wax, etc., and must be sufficiently dry. Cementitious substrates must not shrink after laying the tiles. Therefore, in good weather, render must be cured for at least one week per cm of thickness, and cementitious screeds must be cured for at least 28 days, unless they are made using special MAPEI binders for screeds, such as Mapecem and Topcem, or preblended mortars, such as Mapecem Pronto and Topcem Pronto. If the surface is too hot due to direct sunlight, cool it down with water ensuring no standing water remains on the surface.

Gypsum substrates and anhydrite screeds must be perfectly dry, hard enough for the final intended use and free of dust, prime the substrate with Primer G (neat) or Eco Prim T Plus (diluted 1-2 with clean water). Substrates on which thin porcelain tiles are to be laid must be perfectly flat. Therefore, where necessary, even out the substrate before laying the floor with a smoothing compound from the MAPEI range. Where required, waterproof areas using suitable MAPEI waterproofing system such as Mapelastic Smart, Mapelastic Aquadefense and Mapeguard UM 35, prior to installing the selected tiles.

Mixing
Pour 5.2 - 5.7 litres of clean water into a clean mixing bucket. Add a 15kg bag of Ultralite S2 powder and mechanically stir until a homogenous, lump-free paste is achieved. Allow the mix to stand for 2 minutes then briefly stir again. When blended as described above, the mix lasts for approximately 8 hours.

Applying the product
Apply Ultralite S2 on the substrate using a notched trowel. Use a trowel with a notch size which guarantees complete buttering of the back of the tile. To guarantee a good bond, apply a thin layer of Ultralite S2 on the substrate using the smooth side of the trowel and then immediately apply another layer of Ultralite S2 to the thickness required using a suitable notched trowel, according to the type and size of the tiles, to guarantee that the backs of the tiles are well buttered. When installing tiles on floors, externally or in wet areas it is important to ensure 100% coverage is achieved, this can be done by spreading the adhesive on the back of the tile to ensure complete buttering. When laying thin porcelain tiles, we recommend that the adhesive is also spread on the backs of the tiles (with the suitable notched trowel) to guarantee there are no gaps to avoid the risk of fracture when in service.

Installing the tiles
The tiles do not need to be wet before they are laid. However, if the backs of the tiles are particularly dusty, wash them by dipping them in clean water. Install the selected tiles into the applied adhesive bed using a twisting/sliding motion to ensure full coverage. The open time for Ultralite S2 is at least 30 minutes in normal weather and humidity conditions. When laying conditions are not ideal (direct sunlight, dry wind, high temperatures), or if the substrate is particularly absorbent, this time may be reduced to only a few minutes. Keep checking the adhesive to make sure skin does not form on the surface and that it is still fresh. If skin forms, spread the adhesive again with the notched trowel. Do not wet the surface of the adhesive if a skin forms, water does not dissolve the skin but creates a film which impedes bonding. Final adjustment of the tiles must be carried out within 45 minutes of laying. Maximum compressed bed depth 10 mm.