This standard specifies the requirements, classification, sampling, and test methods for rigid expanded polystyrene (EPS) used as thermal insulation material. It classifies EPS into three types based on density (Normal, Heavy, Very Heavy Duty) and outlines mandatory physical properties such as thermal conductivity, compressive strength, and water absorption.
Specifies requirements for expanded polystyrene (EPS) products used for thermal insulation.
Quick Reference Values
Nominal apparent density for Type N (Normal Duty)15 kg/m³
Maximum thermal conductivity for Type N (Normal Duty)0.045 W/(m.K)
Minimum compressive strength at 10% deformation for Type N70 kPa
Maximum water absorption by volume for all types2.0 %
Minimum oxygen index for FR (Fire Retardant) Grade24 %
Practical Notes
This standard is superseded by IS 4671. Always refer to the latest active standard for current projects.
Specify Fire Retardant (FR) grade EPS for applications requiring improved fire performance, and ensure compliance with local fire codes.
Protect EPS boards from direct and prolonged sunlight (UV exposure) during storage and installation to prevent surface degradation.