Holmes on Homes (2003)

S6E11 Clean Slate

Kjirsten and John, residing in a century-old home, renovated their bathroom to include a stunning slate tile shower with built-in seating. However, they soon discover a peculiar substance seeping from the grout and find that the shower isn't draining correctly. As the ceiling above begins to peel, they suspect there’s more to the situation than meets the eye. Mike examines the shower and reveals that, despite its attractive appearance, there are significant issues hidden underneath that could lead to trouble.