Is the use of a membrane behind shower wall tile standard in the UK?

A leaking pipe in the wall means I need to cut/patch (and later replace) the tiling in my shower cubicle. Reading some related questions here, it seems that standard practice is to install a perfectly waterproof barrier below the tiles.

Is this now standard practice in the UK? Previously, I've used cement board, shower grade tile cement and grout (the grout being an epoxy) – and the shower in question doesn't seem to even have that (seems to be tiled over a brick/plaster exterior wall).

Luckily the tile came off intact when I cut through it, it is fixed directly onto the plaster (so this will be a patch rather than replace this time round):