Recommended For: â¢ Reducing the depth of joints in construction and glazing use. â¢ Creating a backstop to allow proper sealant tooling in expansion joints. â¢ Temperature range: -70ÂºC to +90ÂºC. â¢ Thermal Conductivity: 0.04 w/mK @ 20ÂºC. â¢ Water vapour transmission: less than 4g/mÂ²/20mm. â¢ Water absorption: less than 1% v/v after 24 hrs. â¢ Density: 35kg/mÂ³ approx. â¢ Heat shrinkage: after 96 hours @ 80ÂºC - less than 1%. â¢ Does not rot. Physically and chemically neutral.