6mm hardibacker for tiling walls?

[RrogerD]

I'm battening around the bath and then plan on using Hardibacker before adding 600 x 600 marble effect tiles. The specs on the suppliers websites mention the use of 6mm hardiebacker for floor and worktops but do not mention walls. Will 6mm be suitable or should I be using 12mm? Particularity in consideration of the weight of the larger tiles? Obvs in using 12mm, I can butt up with 12mm plasterboard for the areas away from direct moisture.

Any thoughts or comments please?

Thanks

 

[DAZB]

For the relatively little extra cost just go with the 12mm.