When mould infestation appears in damp materials, in most cases bacteria, mites and protozoa will also be present. All these organisms are microscopic in size and are therefore referred to under the umbrella term of microorganisms.

Moulds are a natural part of our environment. Because of this, mould spores can always be detected both inside and outside buildings.

The requirement for mould growth is always dampness. The causes are many and varied: excessive humidity in a room, furnished wall covering within external structures, residual building moisture (especially with new builds!), infiltrating moisture from outside, or thermal bridges. In the event of, for instance, water damage, leading to moisture penetration of building parts, wallpaper or inventory stock, then the mould spores already present are highly likely to be activated and grow. Eliminating sources of damp is the only way to keep mould under control in the long term.

The following conditions are required for micro-bacterial infestation in buildings:

• At least one microbe (spores or part of a hypha)
• Moisture presence within materials or air humidity greater than 80% rel. humidity
• A food supply, e.g. wood, leather, wallpaper, plasterboard, paper, paint, etc.