t5_nel

Thanks for the comments guys a few things to say

1)Parquet is definitely all coming up this time!
2)Good news about ply thickness
3)Is cement backer board the same stuff as 'marmox' and wedi board?
4)Can you really nail this board? This sounds much faster!!! How much does this typically cost per sq m. over 40 - 50 sq m.?

The reason I am concerned about levels is because some tiled areas are fine (kitchen , cloakroom) as they did not have parquet originally. 6mm marmox board on a bed of some mapei adhesivewa used to bring the level of these rooms up to parquet level so that the door thresholds would be pretty level.

I am very interested in the cement board idea but I am worried that this will be an arm and a leg in terms of cost.