Important Changes of Polyisocyanurate R-Values
To Take Effect January 1, 2014 The Polyisocyanurate Insulation Manufacturers Association (PIMA) recently reported changes in determining the R-Value for polyiso. An update to ASTM C 1289-11 has revised the certification of Long Term Thermal Resistance (LTTR) values that will go into effect January 1, 2014. These changes shouldn’t impact the 2010 Florida Energy Conservation Code since the code is based on prescribed performance requirements (resistance values) of the insulation. With that said, these changes may impact the cost of and the amount of material used to achieve the required thermal resistance. In the case of existing roofs the 2010 Florida Existing Building Code is clear in section 601.2 Conformance. An existing building or portion thereof shall not be altered such that the building becomes less safe or energy efficient than its existing condition. Be aware that because the R-value per inch will be reduced by these changes, using the same thickness o...