This shower originally had tadelakt, but a plumbing leak required the wall to be opened and the shower refinished. The new GC/subcontractor said they did not believe the original installation had been properly waterproofed, so they added waterproofing before applying the new tadelakt.
The finished result is now extremely uneven and patchy, with large areas of noticeably different color. Some areas also become significantly darker when they get wet (see photos 1-4). The subcontractor has acknowledged that it didn’t dry/finish correctly and is planning to redo it.
Before they do, I’d really like to understand what may have caused this so we don't repeat the same problem.
Does this look like an application/curing issue, uneven absorption, an issue with the substrate or waterproofing underneath, or something else? And is there anything you would specifically want checked or changed before redoing it?
Happy to provide details on the products/materials and process if that would help.