I've been doing loads of work at a house for a customer- they have recently moved in to this place. There is an ensuite wetroom with rather small tiles on the floor all under 100mm2. So loads of grout lines as there are loads of tiles. I had to fix some loose tiles back down and regrout- which I did properly. I then coated in Thompsons water seal- as a secondary measure against water ingress. Maybe not the best idea- but I thought it would suffice. So some of the grout is cracking- due to movement, temperature etc I imagine (note- I didn't fit the wetroom- so have no idea how well it was done in the first place). What I need to know is - can anyone on here recommend any flexible sealants to coat the whole of the floor area, which will give a clear, watertight, flexible coating, even something quite thick like 1 or 2 mm or more? Was thinking something along the lines of swimming pool tile sealants.. Thanks in advance.