Description ARDEX S28 Tile Adhesive is a rapid hardening and rapid drying tile adhesive with specific properties for fixing moisture sensitive natural stone floor tiles, as well as porcelain, mosaics, fully vitrified and ceramic tiles, in internal dry locations. ARDEX S28 has a unique semi-pourable consistency ideal for fixing large format floor tiles. ARDEX S28 Tile Adhesive is white in colour and is supplied in 20kg bags.ARDEX S28 incorporates ARDEX Rapidry Technology meaning that the mix water is totally bound into the hardened adhesive which virtually eliminates the risk of water staining of moisture sensitive natural stone tiles, or the mix water affecting wooden substrates. It is ideally suited to fixing translucent stones and natural stone where a light coloured background bed may be required. The designation C2 FTE S1, in accordance with BS EN 12004, classifies ARDEX S28 as ‘improved fast setting cementitious adhesives with reduced slip and extended open time.’ The additional characteristics of ARDEX S28, determined in accordance with the test standards listed in BS EN 12004, are a tensile adhesion strength of greater than 1 N/mm² adhesion value. The mixed mortar has an extended open time of up to 30 minutes, and an easily workable, semi-pourable consistency to facilitate the solid bed fixing of large format floor tiles. ARDEX S28 adheres strongly to most construction materials such as concrete, cement and sand screeds, heated sub-floors, anhydrite screeds, and existing ceramic tiled surfaces. Surface preparation:The backgrounds and surfaces to receive the tiles must be clean, firm, free of dust, dirt, oil, grease and other barriers to adhesion. Ensure that the background has adequate drying time, as given in the relevant part of BS 5385-3:2007, prior to fixing the tiles. Install tiles in accordance with the relevant parts of BS 5385 and BS 8000: Part 11 Workmanship on Building Sites. Backgrounds to receive ceramic tiles should be finished to Surface Regularity 1 i.e. so any gap under a 2m straight edge does not exceed 3mm. ARDEX S28 Tile Adhesive can be applied to dry or moist surfaces, but moisture sensitive materials must be dry and remain dry after fixing. Mixing:ARDEX S28 powder is added to clean water in a clean container whilst stirring and mixed thoroughly to give a semi-pourable, easily worked mortar. The use of an ARDEX mixing paddle with a 10mm chuck, variable speed electric drill makes light work of mixing. The mix proportions by volume are approximately: 3.5 parts ARDEX S28 powder to 1 part water. A 20kg bag of ARDEX S28 requires approximately 6.6 litres of water. Do not exceed the maximum water content. The consistency of the adhesive can be adjusted to suit site conditions and the materials being fixed. The mortar should be applied at temperatures above 5°C. The pot life of the mixed mortar is approximately 45 to 60 minutes at 20°C. Application:The mixed mortar is applied to the prepared surface with a trowel and then combed through with a suitably sized notched trowel in straight ribs to give a ribbed mortar bed. The tiles should be fixed within the open time of the applied adhesive and pressed into place with a twisting and sliding action ensuring solid bed fixing is achieved. ARDEX S28 is classified as having an extended open time of not less than 30 minutes with freshly mixed material when measured in accordance with BS EN 12004. For optimum performance under typical UK site conditions tiles should be fixed within 20 minutes, and can be adjusted for up to 15 minutes at 20°C. Grouting:Grouting can proceed once the tile bed has hardened sufficiently so that the tiles will not be dislodged. When grouting floor tiles, ARDEX S28 is normally hard enough after 2 hours at 20°C to accept foot traffic, depending on the porosity of the tile and the background. Higher temperatures will shorten and lower temperatures will lengthen these times. The tile joints should be grouted with the appropriate ARDEX-FLEX Tile Grout. For moisture sensitive natural stones consider the use of ARDEX MG Grout to reduce the risk of picture framing and water staining. Coverage:A 20kg bag of ARDEX S28 will yield approximately 18.1 litres of mortar, using approximately 1.1kg of powder per m² per mm thickness of adhesive bed. The actual coverage achieved in practice will depend on the back profile of the tile, notched trowel and technique used to bed the tiles e.g. a 20kg bag of ARDEX S28 will cover approximately 6m² at 3mm thickness. Technical Data: Weight of fresh mortar approximately 1.4kg/litre Working time (20°C) approximately 45-60 minutes Adjusting time (20°C) approximately 15 minutes Product Datasheet Click here to view this product on the manufacturers website.
