A shower tile leak is often one of the first bathroom issues a homeowner notices. It may look like a single grout-line problem, but the cause is often more layered.
When it may be mostly a surface issue
If aging grout or failed sealant is the main issue and it is caught early, regrouting or resealing may help.
When deeper waterproofing problems may be involved
If moisture is showing on the wall behind, at the outer base, around the door trim, or even below the room, the issue may already involve deeper layers.
Why the visible grout line is not the whole story
Once water enters through a tile joint, it can travel internally, so the place where the problem shows up is not always the place where it started.