Thanks for the advice.
With respect to the floor, I am reluctant to remove and replace the 6mm ply as it has already been tanked. The ply is screwed down at 10 cm intervals onto brand new T&G, this is also well screwed down. What are the risk if I continue and what are my options?
Also WRT...
I am a general DIY'er and have previous experience tiling bathrooms and kitchen floors.
My question is which trowel should I go for on a 30cm x 60cm porcelain tile (same tile, different colour) going on a tanked walls (two plasterboard, 2 plastered) and floor (new T&G with 6mm plywood 10cm...