Why does white bathroom grouting turn black? And what can be done to prevent it?
• The black staining on the grout is the fungus . It thrives in warm, damp areas, and the grout surrounding bathroom tiles is an excellent habitat for it. Applying neat bleach and bicarbonate of soda, then scrubbing with a toothbrush, will remove the mould. Unfortunately, the fungal cells can penetrate mastic and leave a permanent black stain. If that happens, the mastic will have to be gouged out and replaced.
It is hard to prevent the fungus from appearing in the first place.…
