Why you should hire a professional.
Often times people shop around for the best price but overlook quality. And sometimes what looks quality is anything but under the surface. Take this shower for instance.
On the surface it looks pretty good. But it is actually a complete failure, because they didn’t use a shower pan liner or any type of waterproofing. It was leaking on all sides and even saturated the carpet in surrounding rooms. On top of that, whoever did this job originally, decided to put plywood over the concrete slab, then they added Ditra underlayment, but no Kerdi or waterproofing. They just installed cement board and set tile.
The mud bed was still saturated even after 4 months of drying out. And even worse, the plywood under the mud and Kerdi was still soaking wet and had black mold growing underneath.
As shown in the above illustration, mold is a very serious health risk.
This is why you should hire a professional tile contractor with proper training and experience.