Glossary - I
Impervious
An impervious paint system is one which will prevent the passage of moisture or moisture vapour.
Inert pigments
Materials which are resistant to attack by chemicals normally encountered in the environment in which they will be used e.g. atmospheric pollution.
Insulation board
Commonly refers to soft fibre board but can also be used for similar boards of any composition.
Intumescence
To swell enlarge or expand when exposed to heat. Many fire retardant materials have this property.