Thanks for your question Tom. Large format tiles are becoming more and more popular as they give walls and floors a more open look. But while they may be more aesthetically pleasing, large format tiling has its installation challenges.
Tile weight is a major consideration, whether tiling onto floors or walls with large format tiles. A heavy large format natural stone tile that settles into the tile adhesive can cause “lippage” – where one edge of a tile is higher than adjacent edges.
Floor substrates must be flat before you begin tiling, as a substrate that isn’t flat to begin with will exacerbate an uneven floor problem as the tiles are installed.
When choosing your tile adhesive with large format or natural stone tiles, consider a pourable thick bed adhesive such as Dunlop CLF-03 Flexible Large Format & Natural Stone Adhesive for floors (or Dunlop CF-03 Flexible Fast Set Tile Adhesive for wall tiling). Dunlop CLF-03 Flexible Large Format and Natural Stone can be used at a bed depth of up to 25mm – this makes it ideal for tiles/slabs of uneven thickness and uneven surfaces in small areas.
Apply the adhesive to the floor surface using a large format trowel with 20mm round notches – this helps ensure “solid-bed” fixing. With large format tiles it’s essential that no voids are left beneath the tile. Check the coverage by lifting the tile up, if a solid bed is not achieved or when laying stud backed tiles it may be necessary to “back butter” the tile with adhesive also.
After each tile is laid, it’s a good idea to check the tile is flat with a spirit level – if it’s not, use a rubber mallet or something similar to level it up.
When using an adhesive such as Dunlop CLF-03 Flexible Large Format & Natural Stone Adhesive, you should leave a minimum 3mm grout joint in line with British Standards and help with sizes of tiles, and grout with a flexible floor grout such as Dunlop GX-500 Flexible Wall and Floor Grout.
Want more tiling advice? Take a look at the Dunlop Blog – here we take some of the best tweets we get, and turn them into helpful tips and advice.