Bathroom floor

[sbj72]

Hope someone can help?

We recently moved into a house. The house has a side extension. We decided to replace the kitchen. Part of that is in the extension. As we ripped out the kitchen we noticed that the stud wall between the kitchen and downstairs shower room was wet.

We decided to rip out the shower room as well, it turns out the shower has been leaking and the stud wall and concrete floor was absorbing the water and were wet!

We have replaced the wall and have left the floor to dry out for about 4 weeks. We replaced the shower tray with a stone one. Today after another 4 weeks i have taken up the shower tray to plumb in the shower, and to my shock the concrete floor under the tray is covered in white furry stuff!! (please see photos attached). This is nowhere else in the bathroom, just under the shower tray!

Has anyone had this before? I beleive it may be salt escaping from the water that leaked as the weather has been humid and no one has been in the bathroom

, but i am more worried it may be mould?

If someone can help, and how to treat it, i would appreciate it.

Thanks

 

[PrenticeBoyofDerry]

Looks like efflorescence, clean-up required. Diluted bleach solution, then warm soapy water and then warm clean water rinse. Leave to dry or heat dry.