marmox onto ply

[Bubblecraft]

I would treat Marmox as I would Hardibacker or Warmup boards. Personally, I'd fit 6mm on a ply floor unless I needed better insulation or a greater heat output from UFH.

Each to their own though.

 

[DHTiling]

The OP does not say it is 18mm over floor boards etc .. ? so as an over lay to joist covering then 10mm 🙂

If it is an overlay to floor joists covering , then use Dural CI or Ditra..

 

[Rookery]

Assuming a stable floor, I would use 6mm Hardie over a timber floor, 12mm if height wasnt an issue. If UFH was involved, I'd use 10mm Marmox/Wedi/Warm Up etc, or 6mm if height was an issue. I believe that Marmox/Hardie/Warm Up to be more thermally efficient than Hardie and is also waterproof whereas Hardie is water resistant but stronger. Thats my view anyway.

 

[Bubblecraft]

Spot on Rookery