scope:

Specifies a method to determine the thermal transmissivity of a moist material under steady-state moisture conditions, i.e. not affected by moisture movement. It is measured using standardized guarded hot plate and heat flow meter methods, at temperature above 0°C. This material property is a function of the moisture content and does not represent the thermal performance of a material under service conditions. However, it can be used, together with knowledge of the moisture conditions in the material, to predict the practical thermal performance.