If you PM him you will get a straight answer
Discuss Grout joints for 1000x1000 Porcel-Thin in the Tile Adhesive / Grout Advice area at TilersForums.com.
Has the heating been commissioned ?
Reply to Grout joints for 1000x1000 Porcel-Thin in the Tile Adhesive / Grout Advice area at TilersForums.com