mould growth within buildings

The majority of buildings contain mould spores, but some buildings are mouldier than others. Indoor moulds can be remarkably tolerant of dry conditions but none can live without some minimal moisture source for a prolonged period of time. Excessively mouldy buildings generally have a source of moisture leading to unusually excessive mould growth. The source of the moisture may be a moist sub-floor environment, a dripping pipe, a leaking roof or some other fairly obvious cause. In many cases the mould can be readily seen growing on walls or other materials in contact with the moisture source. Sometimes the moisture can occur inside walls and not be visually apparent. A common but not so obvious cause of moisture in colder winter months is condensation inside south facing walls.