How to Waterproof a Shower Niche Before Tiling?

[Legolas]

I’m installing a recessed shower niche in a stud wall. What waterproofing membrane/system do you trust most—liquid-applied roll-on, sheet membranes, or a waterproof backer board? Looking for something DIY-friendly but durable.

 

[Look what I found]

I used RedGard liquid over Wedi board. You need two coats of RedGard (with proper drying time), but Wedi panels make shaping niches a breeze. No mold issues so far after 2 years.