Wedi/marmox showerlay

[Pudding]

Hi all
First post here so please be gentle!
I am about to start on a refurb of our ensuite. Have a couple of questions.
I am planning to mount the showerlay tray on a raised plinth 4*2 timber, 18mm wbp and then the showelay former. On the walls I am mounting wedi board 12.5 mm on to the stud work and dot dab on 1 wall.
The questions are:
Should the wedi boards goto the floor with the plinth/tray butted up to the boards or the boards sit on top of the tray?
Then am I ok to use the marmox sa waterproof tape on the mixture of wedi/marmox products and does this tape need to be feathered in with some adhesive or can I tile straight over the tape.
Thanks in advance for your help
Regards
A

 

[SJPurdy]

I have always fixed the floor/tray elements first and then fitted the wall boards so that they sit on top. My logic for this is that the joint is horizontal not vertical which thinking about it shouldn't make any difference as the joint will be sealed anyway! A big disadvantage in laying the floor elements first is that they are easily damaged when working on to fix the walls so will need protection. After reading the question I have checked a Wedi brochure on fitting their Fundo shower base and I note that in their pictorial instructions the walls have been fitted first and the shower base is butted up to the walls.

I recommend the Wedi 610 sealant to seal all the joints between boards and to the shower base (assuming it is similar to the Wedi one - I've never seen the Marmox version). For my peace of mind (good practice) I would also secondary seal the crucial corner joints (including floor/base to wall) with Wedi sealing tape or similar.

 

[Qwerty]

[MENTION=29123]SJPurdy[/MENTION] has summed it up nicely. I seal joints twice as well, one with a sealant type waterproof flexible mastic (not silicone!) and then again with a tanking tape/ band embedded with tanking gum