Vapour control layers are used in roof and wall installations to ensure long-term protection to the building envelope. Air and vapour control layers improve the building’s air tightness and prevent moisture within the building’s warm air from reaching the insulation layer. Air and vapour control layers ensure that the building envelope is properly sealed to control ventilation and prevent heat loss in compliance with Building Regulations Part L. Installed on the warm side of insulation, vapour control layers protect insulates from interstitial condensation. Specialist membranes with additional characteristics, such as high UV resistance, ventilation control and energy efficiency, are also beneficial for the building’s long-term protection.
British and international building standards specify flame retardant materials for specific installations and structures. Flame retardant additives are incorporated
in the materials or added as a coating to make them flame retardant; it is the formulation, quality and amount of these additives that determine which flame retardant tests the material will pass and what standards to which they will comply.
A flame retardant material is one that self-extinguishes; it does not mean that it is flame proof. Flame retardant materials are resistant to catching fire, reduce flammability, and inhibit, suppress or delay the production of flames. Flame proof materials are ones that are not liable to catch fire or be damaged by fire and are not readily ignited or burned by flames.
In 2002, to harmonise the classification of the reaction to fire for building materials, the European Commission introduced the Euro Fire Class System, based on EN ISO 13501-1.