Fixing tile backer board to concrete floor

Hi Pete,
If you mean hardibacker board, then they recommend tile adhesive and screws. If you go on their website you can watch a video on how they do it. On phone at the moment otherwise would link to it

 

Actually thinking about it I think hardi is only for mounting on to timber.

 

whatever board you use you should use slow set flexi as the cureing rate is the same,Its allways a good idea
to leave expansion joints which can be taped over for wet rooms.Use a 12mm trowel to spread adhesive
use body weight to compress each board as it is laid.Use staggered joints when fixing boards and when complete turn on heating in increments of 3 degrees a day until required temp is reached,the following
years can be started from 10 degrees until temp is reached,never go over these figures.