Floor tiling over liquid screed above UFH

[EdSt]

Hi,

 

Apologies for raft of what I'm sure are obvious simple questions to those in the know. I've found the answers in various different places and in isolation but wanted to try and consolidate them together for responses.

 

I need to understand this bit of my build bang on, so as to get liquid screed level right for tiles to be flush with threshold of sliding doors (Slideandfold's Vista XL model  - not currently listed on their website but give them a call - super helpful)

 

I understand I need to back butter the 9mm tile (looking at Topps tile 1.2Mx0.6M) with thin adhesive layer to fill indentations and ensure full contact. I also get that you press down on the tile to collapse the ridges so the adhesive spreads to ensure full contact, same with the decoupling mat bed below.

 

Questions are:

1) What size notch trowel is best for decoupling mat adhesive?

2) If I use a 3mm decoupling mat, what thickness will I likely end up with for Matt+(collapsed) bed=?mm

 

3) What size notched trowel is best to spread tile adhesive on decoupling mat? 

4) With back buttering the tile and notched tile bed on decooupling mat, what overall tile bed size am I likely to end up with for (collapsed)bed+tile=?mm

(* I assume you don't top butter the Decoupling mat ?!)

 

As I say I need to understand 3&4 to work out finish screed height.

 

Thanks in advance for your all and any help!

Ed

 

 

 

Edited September 22 by EdSt
photo added