I have a client that has an outdoor area tiled with 20mm porcelain (600x600mm) where the grout is breaking out of the joints. It is on a very solid timber platform with (I’m assured) 25mm outdoor grade plywood as the top. It has been grouted with Kerakoll Fugalite Bio which now has come away from the tiles themselves leaving a hairline crack on some bits and lifting out completely in some others. There is no obvious movement in the deck (a full glass of water didn’t spill or indeed wobble with the 16 stone client jumping up and down next to it) and he’s asking for a solution. Any ideas of a product that could be used in place of the Fugabio?