Caution
Water is escaping at or under the tray, usually into the floor rather than onto it, so the damage shows up somewhere else.
Tiles sound hollow, crack in a line, or come away from the wall: the adhesive or the surface behind it has failed.
Low risk
Joints are crumbling, cracking out in lines, or staining black however hard you scrub them.
The white bead round the bath or shower has gone black, and bleach only lifts it for a week.
Water escapes past the door or the frame while you are showering and puddles on the bathroom floor.
The bath gives underfoot, creaks as it fills, or pulls away from the wall: it is not properly supported.
The pan moves when you sit on it, or there is water on the floor around its foot after every flush.
A stain, a bulge or a drip below an upstairs bathroom: something up there is leaking into the floor.
The mirror stays fogged, the walls run with water and mould keeps coming back in the corners.
High risk
A level-access shower is putting water into the floor rather than down the drain: the waterproofing has failed or was never there.
Describe the job and get a fixed price from a local bathroom fitter.
