retiling shower - skimmed boards to bare board transition

[orbit500]

i'm moderate DIYer, more tools than knowledge ...
our 2nd shower was leaking to downstairs so after fannying around a bit noticed grout was cracking on lower course of tiles ( 40x30 5mm ceramic ).
off they came to reveal dot'n'dab onto unsealed skimmed 9.5mm board, grouted corners, the works
took off door, tiles to 90cm height and refixed board with 200mm noggins and foam support - happy there and ready to tank with mapei kit.
question : old boards are 2mm skim plus 3mm adhesive so will need that extra 2mm on the new bare boards.
I'm not keen on skimming so can i just go up a trowel to 10mm which should compress to the 6mm total thickness ? Assume the Mapei has nominal thickness ( actually seems to be 1-2mm so maybe no change needed )

 

[tpt]

Yep, making up 2 mm with tile adhesive is fine

 

[orbit500]

thanks, appreciate that. i have white star - will be ok for these tiles ?

 

[tpt]

if you are going by the book they are a bit big for a tubbed adhesive, especially on a tanked background. you'd be better off with a cement based bagged adhesive.

That said, those guidelines get broken lots, and theres a good chance it will be fine