Unfortunately problems of dampness can be quite complex; a sensible starting point is to consider a

definition of dampness and to examine how water is held in materials.

plastics and metals) are porous and will always contain some moisture. Assuming there are no problems

of condensation, spillage, or damp penetration through the fabric, the moisture they contain will vary

according to the relative humidity of their surroundings. This is why it is so important to ventilate

timber ground floors. Inadequate ventilation, particularly if the ground below the void is wet, will allow

the relative humidity of the air below the floor to rise. This occurs because the air steadily absorbs water.