How do I fix and grout natural stone tiles?

The main issue associated with fixing natural stone is determining if they’re moisture-sensitive or not and, following that, using the correct products to fix them. If the stone is moisture-sensitive, moisture from traditional adhesives and grouts can migrate into the stone and cause discolouration, staining and even warping. If you’re fixing moisture-sensitive stone, or if you’re unsure, use one of our ARDEX Natural Stone Tile Adhesives. These products incorporate ARDEX RAPIDRY FORMULA Technology to ‘lock’ the mix water within the mortar and eliminate the risk of water staining. 
You can use our ARDEX Flex FS or FL grout range for natural stone tiles. We suggest the stone be fully sealed prior to grouting to help prevent grout retention on the stone surface. Always conduct a grout test on a small, inconspicuous area first to check the grout colour and its effect on the sealed stone and that picture framing/moisture staining into the edges of the stone does not occur.
The installation should then be finished with ARDEX ST Silicone Sealant.