The compressive strength of an insulation product indicates how much the material deforms under load. The higher the compressive strength, the lower the actual deformation will be. This is important because excessive deformation can directly affect other layers in the roof build-up or construction application.
For example:
When the waterproofing membrane is applied directly on top of the insulation, a material that deforms significantly under load may cause additional stress at the seams and overlaps. This increases the risk of damage or reduced performance of the roof system.
The most commonly known property used to assess compressive strength is the load at 10% deformation. While this offers a useful comparison between insulation products, it is not a reliable indicator of real-life performance in application. A 10% deformation is often too much, especially with thicker insulation boards. Furthermore, this value reflects short-term performance only. At IKO, we have test reports that provide insight into long-term compressive load performance based on insulation thickness and the applied loads.
If you have a specific application and want to assess the suitability of IKO enertherm insulation boards, please contact your IKO advisor.