In message , Tim S
writes
Tim Lamb wibbled:


Hmm... so it has to be a *click* version? What about the membrane they
seem to insist on?

I used Tredair Boardwalk - seems successful. It's a 4mm dense underlay with
acoustic reduction properties and an integral vapour barrier (foil top).

OK. Noted.

So 15mm for Kahrs mid range plus 4mm underlay.... I'll ask the builders
to allow for 20mm flooring in the main area. On line ceramic tile
suppliers are rather coy about publishing tile thickness but the
existing total 13mm so I may attempt a different screed height for the
entrance and shower room.

regards

--
Tim Lamb