How best to bring flooring to level of wet room former befor tiling

[Reluctant Robin]

My brother who is a retired joiner, with a little tiling experience, and myself who doesn't have any, are intending to create a wet room type ( with screen) bathroom. I think I may end up with lots of questions, but the main one at the moment is, what is the best method of making up the difference of 18mm ply, with 6mm backing board and then under floor heating, to a 26mm former which has to be bedded in with tile adhesive. As I want the heating mat , or Wire, I haven't decided which one yet, to be laid over the shower former as well as the rest of the floor I imagine that is essential that the whole lot is level before tiling, so how best to achieve this please??

 

[Qwerty]

Yes, floor & former to same level before tanking & tiling. You can always use self levelling compound to make up the desired level. My personal advice is to avoid the heating mat on the former, but that's up to you

 

[Bill]

Your former should sit on your joists (if wooden floor) and this will reduce the height difference.

Watch this video for a simple way to do it.