Why does condensation form?
Air tends to hold only a certain amount of water vapour and the warmer the air is the more it can hold. Once the air reaches a cold area to which it is often attracted such as damp or cold walls, windows/surrounds, and non insulated roofs etc. the water vapour turns into droplets of water. Areas that also tend to get affected by condensation and black mould spores are cold walls where furniture is pushed up to that results in a lack of air flow.
