Mould

More and more inquiries regarding moulds growing on ceiling linings. Most owners regard moulds on ceiling as signs of roof leaks.
In most cases moulds growing on ceiling lining has got little if any relationship with roof leaks and often caused by combination of a number of reasons such as:

1. Lack of or insufficient or unevenly distributed ceiling insulation
2. Poor home natural or mechanical ventilation
3. Poor subfloor ventilation
4. Poor ceiling lining material or coating
5. Lack of general maintenance
6. Excessive surrounding vegetation
7. and other factors 

It normally associated with old houses and not too hard for owners to find out reasons by themselves.
In most cases the solution would be a combination of a total roof service by a roof maintenance professional, retro fit of new ceiling and under floor insulation, installation of heat pump and/or home ventilation system, general cleaning, landscaping maintenance and so on.