Why it matters
Interior caulking has a life of 5 to 10 years, per InterNACHI. Tile lasts 75 to 100. That mismatch is the whole story of bathroom failures: the tile is fine, the seal around it is not, water gets behind it, and now you have a subfloor problem inside a bathroom that looked perfectly nice in the photos. This is the exact seam where Casaroo's two scores meet, and it is worth being precise about which side a finding falls on. Cracked, discoloured, or missing grout in a dry area is cosmetic: it prices per square foot and it is a regrouting job. Failing caulk at the base of a tub, a soft floor near the tub, or staining running down from a shower is not cosmetic. That is water going somewhere it should not, and it belongs on the mechanical side until someone has looked behind the wall.
How to spot it
Grout that is dark, crumbling, or missing in the joints; caulk lines that are cracked, peeling, or blackened; tiles that sound hollow or move (a tell you can only get in person); a mismatched patch of new grout, which means someone already had a problem here; and staining or swelling on the floor where the tub meets it.
What it costs
Regrouting is a modest, labour-driven job and is one of the highest-value hours anyone will ever spend in your house. Full retiling runs $10 to $20 per sq ft installed in the GTA, and tile labour is billed at $65 to $100 an hour, which is why a small bathroom costs what it does.
What to do
Monitor, and act early. If you buy the home, replacing the caulk around a tub is a weekend and a few dollars, and it is the single cheapest piece of preventative maintenance in the building.
Education and triage, not a home inspection. Casaroo can see failing grout and caulk in your photos and will name it. Whether water has already gone behind the tile is something only an in-person look, and sometimes a moisture meter, can answer. We flag; we don't inspect.