Extending size of wet room former, best way?

[WiltshireWarrior]

What’s the best way to extend the size of a former ?

This is to replace a failed installation so the size of the area is fixed and the former I have is the largest I could find.

There will be a 4” gap around two edges (the former is pushed in to one corner of the larger area) that I’ll need to bring up to the level of the former. Those extra 4” strips will also be the base of the shower.

sand and cement
Self levelling
Ply ??

obviously I’ll seal snd tape the edges between the former and whatever medium I use but what’s the best way to do this ?

I have the agony of several choices....

 

[Swwils]

Just use brand compatible tiling board... They are all designed to be able to be expanded and jointed to a former like this when jointed properly.

The detail will be in whatever transition you have to the falls that exist and is why linear drain is generally easier and better looking for larger areas.

Also a made to measure former is not that expensive or troublesome.

Or alternatively cut a larger tray down.

If you have room you could also consider a wall drain.