Insullation mats over cement board?

[2020Tiling]

Hi, just a bit confused when to use insulation mats on floors . I have a 6 mtr bathroom floor to tile , chip board but will be over boarding with 6mm cement board then fitting ufh mats . Would I need insulation mats on this job? Thanks

 

[Sean SML Tiling]

You dont have to use them but I normally do as you dont loose amy heat with them

 

[Ajax123]

If you put insulation boards on top of the cement board what would the point f the cement board be??

 

[Ian]

As Alan says, it's one or the other. Cement board if no UFH, insulation board/heat wire/SLC for UFH install.