1200mmx900mm shower alcove build

Hi All

Just bought a new house and I've knocked the toilet and bathroom through into one. I'm moving the toilet and I want to build a shower cubicle in the space where the toilet was. The space is 1400mm so I was going to put down a 1200mm shower tray and use the 200mm "gap" to have a concealed thermostatic shower to get a "minimalist" look. So I need to build a small fake stud enclosure to enclose the 1200mm shower tray on 3 sides and just have sliding doors so it looks like it was always meant to look like that.

I think I am being really thick but if I build the studs then line with 12.5mm cement board so that the tray sits in the space, when I tile it up and the tile sits on the shower tray, won't the thickness of the tile on either side plus the adhesive mean that the width of the gap for the door is much less than 1200mm? I'm worried that the shower doors won't fit?

Any advice would be much appreciated!! Thanks!

Buy the door first?

Shower screens have tolerances within the depth of the wall profiles that allow you to position the frame within min and max widths of the enclosure.

If you take roughly 10mm for tile thickness and 3mm for adhesive on both sides, that gives you a 26mm reduction.

When looking at screens, make sure you find out what the min and max spans are, for that particular screen, as each manufacturer varies.

A 1200 door will usually be adjustable, so 1170-1210 or 1155-1205 for instance.