Mould growth is caused by either building defects, which wets building elements, or by condensation. Mould growth will develop on walls, furnishing, and clothes once dampness is present for a period of time. Mould fungus needs three conditions to grow (infection, nourishment and a damp environment) and these will be present in a dwelling once a damp environment is established for a period of time. It is considered by some that the presence of mould within buildings can contribute to serious health risks. Toxic moulds can cause a range of symptoms including headaches and a wide range of skin lesions and rashes. The areas where mould is located need to be treated using a suitable fungicidal wash. But this is a temporary cosmetic solution and the cause of the appearance of the mould, the damp environment, needs to be dealt with prior to redecorating.