insulation board on chipboard..

[diamondtiling]

plastic ply here you go

Nicobond Plastic Ply Tile Backer 1.2 SQ.M | Backer Boards @ Vista Tiling Ltd

I do not like the look of that stuff at all, it looks very flimsy.

 

[macten]

NMP has excellent insulation properties

 

[diamondtiling]

NMP has excellent insulation properties

Only if you use the premium boards.

 

[DHTiling]

You still need to screw marmox type boards to timber floors as well as using flexi addy... and use the appropriate washers and screws.