FOUNDATION ( Screed or cement plaster)
• Prepare the screed or the plaster using cement mortar and wait its ageing until it reaches a residual humidity < 2% (waiting time: about 1 week for each cm of thickness). The screed must be thicker than 5 cm and respect the existing joints.
• Before the laying, check the screed and the plaster suitability. These must be: insulated, dry, stable, solid, sufficiently flat and free from loose material, dust, greases, oils, waxes, paints, detaching agents and any other item which may reduce adhesion.
• Correct any irregularity with levelling and auto-levelling products, taking care to verify the perfect planarity of the plane which mustn’t have level differences higher than 2 mm.
LAYING AND FILLING
• Spread the adhesive on the foundation and lay the Pander Terrazzo Tiles on the wet adhesive before it forms the superficial pellicle. In case of high temperatures and ventilation, the open time of the adhesives (indicated in the specifications) can notably change. Before the laying, we suggest you to plunge the tiles in clean water for a few seconds and then drip the excess of water away, in order to guarantee a safer grip between the tile and the foundation. Carefully press in order to get a flawless adhesion and level the tiles with care and precision, to avoid differences in level among the tiles. Any excess adhesive which comes to the surface during laying must be removed immediately with a wet sponge, to prevent damages to the surface.
• The width of the laying joints (grouts) must comply with the European standards (width at least 2 mm, so that the sealant can penetrate to the required depth at all points). In any case, the dimensions of the tiles and the thermal expansion coefficient could determine the choice of joints having a different width, especially for outdoor flooring. Existing expansion joints must coincide with joints in the tiles, and subdivision joints must be provided (for great surface panels of approx. 16 sqm), always following the suggestion of the person in charge for the laying.
• Laying must be carried out using adhesives specially developed for laying stone and cement agglomerates. As an indication, we can suggest the following adhesives: FLEX white, H40RAPID or H40 MARMOREX (produced by company KERAKOLL) or other products with equal technical characteristics, to use following the instruction of the supplier company, also in relation to the weather situation.
• The filling of joints must be performed while the adhesive is not yet completely hardened, using professional and colored fillers like FUGABELLA (KERAKOLL) or similar products with color as similar as possible to the color of the tile. The cleaning of the filler must be done within the right time (while still fresh) by using a sponge and clean water. Pay attention to colored fillers which may stain the tiles. If necessary, protect the floor before the filling operation.
• Important: absolutely avoid covering or protecting the tiled floor with cardboard having coloured writings, magazine pages, plastic, nylon or adhesive tapes.