The Thermal Conductivity (k value) of new IsoBoard is 0.024W/m°C, and that of 5-year aged IsoBoard at 90% relative humidity is 0.03W/m°C, which is referred to as the “long term design” value. The Thermal Resistance (r value) of IsoBoard is calculated by dividing the thickness of the IsoBoard by the Thermal Conductivity (k-value), to achieve the table below.
For SANS10400XA r-value calculations the k-value of new IsoBoard of 0.024W/m°C can be used, but IsoBoard recommend that the “long term design” value be used when doing a Rational Design. Because IsoBoard is expected to last for the life of the building, using an aged value allows a confident prediction that required thermal performance standards will continue to be met.
Thermal Conductivity tested to SANS 8301
IsoBoard thermal conductivity k value
0.02624 W/m.K - Test result available
Thermal Resistance (m.°K/W)
Thermal Transmittance (W/m2°K)