It is unlikely to be a condensation issue with paint peeling, although this is possible. I would suggest in the first instance that the plumbing be inspected to ensure that there are no leaks from the water pipes or wastes. If no leaks are detected then condensation may be responsible. In this case you would likely require an electrician to ensure that the shower room is correctly ventilated using an extraction device.
Peter Barber CSSW.,CRDS.
Structural Waterproofing Surveyor.
Projects that add value to your home - Phil Spencer
Looking to extend your home but don't know where to start? Property expert and Rated People ambassador, Phil Spencer, shares some thoughts on why loft conversions are such a popular way to create more living space and add value to your home.