thinset

[ricpooley9]

Hi, I am tiling my conservatory which is 28' x10'.
Firstly there is exterior grade chipboard down, i have now screwed every 8" and pva glued down sheets of 6mm exterior ply over that (i am aware this should have been thicker but its down now!), i have 30 sheets of 6mm hardie backerboard arriving this week (and the correct hardie screws!), and also flexible adhesive and flexible grout for my tiles.
My question/problem is this, what do i use under the backerboard before screwing them down? Every person on every single forum on the internet goes on about thinset, i cant find it for love nor money though, where do you get it from and what brand is it??
Many thanks

[darrenba]

Thinset is basically an American term for bagged Tile Adhesive. So use any flexible bagged tile adhesive - grey is usually cheaper

[ricpooley9]

Thanks for that will get some picked up!