'Mould' in cold watertap upstairs

[sander]

For some reason the taps upstairs have black mould accumulating (only the cold water ones), the same for the showerhead whilst downstairs we do not have this problem.

Would anyone have an idea to what this could cause, I was thinking cold water tank in loft, pipes etc.

Any advise will be helpful. If the water tank, what can be done to clean this?

Thanks

[Peter Parry]

It is probably airborne mould growing on condensation or a slightly leaky tap, it is probably fairly widespread but not noticeable elsewhere. The shower head and cold tap remain damp for some time after use and this allows more mould to grow on them. The airborne moulds proliferate in moist air so it might be worth investing in a hygrometer and measuring the relative humidity. If it is high then improving the ventilation in the house should be the first priority.