I'd really appreciate advice/guidance on a flooring issue I have... New vinyl flooring is to be laid on the kitchen floor (either sheet or LVT, still to be decided). Problem is, the sub floor isn't good enough. The current surface is quarry tiles > concrete > hardcore > earth without any DPC (1950's property). There are high spots, low spots and a few areas that sound hollow when tapped but it seems perfectly dry - though I'd like this checked with a hygrometer - who would do that? I'd like a belt-and-braces solution which I suspect will involve digging up the entire floor and re-screeding the lot (even though a new kitchen has already been installed!!) though I'm tempted just to dig up the hollow-sounding tiles, re-screed those areas and leave the rest of the tiles in place. What tradesperson is best to give advice on the prep required and who would normally do this work - flooring expert or builder? Also, is it advisable to lay decent quality sheet vinyl in moderately sized rooms? I've recently been scared off laying sheet vinyl in a 25ft x 12ft kitchen diner on advice from a reputable floorlayer. They advised LVT instead - less chance of tearing.