There have been a few problems reported on the estate with condensation, which is often associated with a black mould growth, and at its worst can sometimes give the impression of serious damp affecting the property, sometimes even resembling rising damp.
The black mould, which can sometimes induce health problems such as asthma, is a sure indication that condensation is occurring, though it does not of course eliminate the possibility there may be other factors at play too, such as penetrating dampness.
Modern flats are generally more susceptible to condensation due to the exclusion of draughts, therefore it is always helpful in such cases to consider how ventilation might be improved, which will prevent excessive build up of humidity within the dwelling. Anything that hinders ventilation can encourage condensation, such as long heavy curtains draped against the surface of a wall, or excessive clutter.
Condensation will tend to occur on the coldest surfaces such as are presented by outside walls and where concrete areas create a `cold bridging` effect. The biggest contributory factor is steam generated in bathrooms and kitchens, so these rooms should be ventilated while cooking and bathing, by leaving a window open or turning on the extractor, and the doors preferably left closed during these activities as the humid air will otherwise migrate to other rooms in a matter of seconds. Keeping lids on saucepans can also help.
The other factor to consider is the level of heating, as warmer air permits less condensation. With this in mind it is best to leave radiators on a low heat even while rooms are unoccupied.
In general a regularly cleaned flat is somewhat less prone to developing the black mould, which does not appear automatically just because there is condensation, but due to the presence or otherwise of airbourne spores, which are reduced in a cleaner environment. That is not to say the mould will not occur in a well hoovered flat if the conditions are otherwise favourable.
Once established the mould is quite tenacious and grows back quickly when bleached off. There are various paints on the market which may have varying ability to inhibit its growth, though the choice of colours is liable to be somewhat limited (to white or white).