Cork works along with an already existing or properly engineered wall as a “Functioning Finish”, often the R Value in a wall is compromised by drafts, convection, conduction, or reflection of energy and the insulating properties are greatly reduced. Cork cannot physically freeze or reach temps above 85 degrees F (30 degrees C), and being projected at the wall it fills all the gaps and cracks that allow drafts. We are also rated with a U value of 0.068 giving, showing at 1/8 of an inch that we can effectively stop the transfer of energy before it reaches your insulation. The performance of cork is not based on an R value, it is based on a K value of 0.068 W/mK which means the heat and cold from outside will not be transferred to the substrate.