By Lisa Breakspear, category manager at Mapei
When installing large format tiles, there are many considerations to make. Safe handling and movement of large format tiles is vital; some of these designs can measure 1200 x 1200 mm. But safe movement isn’t just about specialist frames and lifting equipment. Ensuring that the tile-front is clean is also essential – and often overlooked – in order to ensure full suction-cup adhesion on the tile for safe transport and installation.
To remove all traces of cement, lime and efflorescence, use an acid-based cleaning spray. Look out for a ‘buffered’ acid cleaner, rather than a muriatic/hydrochloric-based solution, for a safer application environment in terms of fumes. At this stage, it’s good practice to clean the underside of tiles as well, to remove any contamination and ensure full adhesive bed contact for a safe installation.
Choice of adhesive is also important. With large format tiles, the adhesive needs to be suitable for the tile size, substrate and application. It should provide sufficient bond strength and flexibility, while allowing enough open time for the tile to be correctly positioned. Achieving good adhesive coverage is equally important; on a tile measuring 1200 x 1200mm, for example, even relatively small areas without good adhesive contact can create weak points. Voids beneath large format tiles can increase the risk of movement or damage, so back-buttering the tile, alongside correct application to the substrate will help to maximise contact and minimise air pockets.
During fixing, it’s generally recommended to apply grout around the outside edge of the tile, rather than ‘flood grouting’. However, this method can cause picture framing. This occurs where grout residues are left around the outside edge of the tile, quite literally causing a framing effect around the edges. To avoid this, any cement-based grout residue should be removed with a suitable ready to use acid-based product as soon as the grout becomes opaque; this is usually within one hour of grouting with a rapid setting formula. If you’re using an epoxy-based grout, then look for a specific ready to use cleaning product that allows cleaning at the point of installation. These products also allow for the builders clean to be undertaken during the installation process.
Large format tile installation leaves little room for shortcuts. Good preparation, good cleaning and the right adhesive, with thorough coverage, will all contribute to a successful result and good performance for years to come.
Category manager at Mapei | info@mapei.co.uk | www.mapei.co.uk
