I have a 1 metre square Aqua Dec and now I find the c.1898 wood floor (8" x 2" on 14" ctrs) on to which it is to sit is not exactly flat.
I've added noggins and set 18mm ply flush with the joists and now I have the former I find it rocks on a joist which is bowed.
Would it be a bad idea to set the former into a bed of adhesive (max probably 6mm) so it has full contact throughout?
I have Keraquick and Latex Plus would they be suitable or maybe Nivorapid would be better?

It will not work that way..

You can line out the insides out the joists with ply (18mm) to be able to get it flat...

Like in this video..explained at around 3 mins in to it.

[ame=http://www.youtube.com/watch?v=3xekpG9Y22k]YouTube - Impey Aqua-Dec Wetroom Installation Guide Part 1[/ame]

These any good? I have been looking at the Wedi base but it need to be recessed into the joist which i cant do on my trusses.

The ones that wetdecs sells, just sits on the joists and no extra supports needed...

Tuffdec2...

Hi Jimmy

Take a look at the Tuff2 showerlay wetroom tray


No underboarding, dedicated drain, lifetime warrantee