What should tile removal protect
Tile removal should protect any sound surface that can stay and expose anything that should not be covered again. A floor tear-out is different from opening a wet shower wall with possible water damage.
Renan uses the removal phase to see the substrate, not to tear out more than needed. If the next step is floor prep or subfloor correction, the demolition should leave a clear view of what needs flattening, fastening or replacement.
