Is a concrete base regulation in modern flats? And is my bathroom floor about to cave in!

Hi All,

The Hapless Home Owner strikes again! I had a rather nasty surprise earlier this week in that I found out that what appeared to be a small leak recently discovered was actually a long-standing problem that has soaked the sub-floor of my bathroom requiring replacement. The Homeserve engineer who delivered this news said that my bath was at risk of falling through so I should get the work done asap. This left me really quite anxious about using and being in my bathroom and the prospect of me, mid-shower, landing in the shop downstairs! Until it occurred to me that all the other blocks being constructed in the area appear to have concrete floors. Does anyone know if this is regulation i.e. that my flat should also have a concrete base? Or how I find this out. Also, what is the actual risk of the bath falling through likely to be? I am a shared owner and am expecting the process of trying to make a claim on the property's buildings insurance laborious and complicated. So, I am trying to decide whether this problem poses such a risk that I should go ahead and just get the work done and hope I get reimbursed by insurance or whether I have time to try and get them to agree the claim up front.

Also, if I do get the work done myself, who do I call??? A carpenter, a plumber, both, some other kind of tradesman? I really have no idea - none of this is covered in my Reader's Digest First-time Homeowner's DIY Manual!!!

Any help or advice would be greatly appreciated.