Hi my tiler screeded my bathroom floor 4 days ago and it hasnt fully cured in places. There also a white powdery residue on top. In some places where its thinnest it has set. In other places not so well - you can walk on it but i tried scraping some of the white residue and slithers of screed would come off with it. The temperature in the bathroom has been about 17- 18 degrees. There's no heating in there yet. He used Nicobond Fibre Flex. Do you think the mix was too wet?