T i m wrote in
:

snip
I put down a layer of the fibre-based laminate underlay under the
carpet tiles in our downstairs WC.

Is that the (typically) green stuff Rod?

The stuff I used certainly was green. And cheap.

snip some more

At the moment our loo has lino tiles that are stuck to the vinyl 'self
leveling' and then the concrete. It is pretty cold in the winter so
you either keep yer feet on the mat or wear slippers but easy to keep
clean ;-)

Ours used to be the as-fitted-when-built thermoplastic tiles onto the
concrete. Except, of course, where the old WC pan came out and was
repaired with some concrete-like muck. It still is but has the underlay
and tiles on top!

--
Rod