ᐅ Bathroom shelf with a waterproof surface

Hello,
can anyone help me? I would like to install a shelf in the bathroom like the ones shown in the two pictures. The drywall construction is already in place. How and with which materials can I finish the surface so that it is waterproof as well as next to the washbasin?
Thank you for your answers.
kris

Nice idea, I like that too!
However, I would only tile the interior surfaces for elegance, to maintain consistent finishes, and to make dusting easier, while leaving the "front" plastered... A shelf like that can definitely handle a few splashes from the washbasin area.

The walls in the shower, especially with level-access models, are coated with "Elastogum" before tiling. This is a liquid plastic (similar to latex paint) that prevents moisture from reaching the material underneath. For the corners, there is a special tape that is applied before coating to ensure complete waterproofing.

I think you can do the same with the shelf, so that if water remains there for a longer time, the drywall panel underneath won’t be damaged. Tile joints are always a weak point.

Best regards, Phidie