On Fri, 10 Nov 2006 11:13:01 +0000 Peter Purr wrote :
It's not wood - some kind of plastic tile over at least a layer of
concrete, but it sounds hollow to me, so I figured it probably wasn't
solid enough to fix to directly.

Quite a lot of flats of that age have concrete plank floors of some
type and the ceiling below is plasterboard on battens.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk