What are the main types of EPS boards in this standard?

The standard classifies boards based on density and compressive strength, typically as Normal Duty (ND), High Duty (HD), and Very High Duty (VHD), with an optional Self-Extinguishing (SE) fire-retardant property.

What is the maximum thermal conductivity for normal duty EPS?

For normal duty (Type ND, ~15 kg/m³), the maximum thermal conductivity is specified as 0.042 W/(m·K) in Table 1.

Are there specific dimensional tolerances for EPS boards?

Yes, Table 2 specifies tolerances for length/width (typically ±2 mm) and thickness (typically ±1 mm), which are critical for achieving tight fits and avoiding thermal bridges.

Is EPS board flammable?

The standard requires that EPS boards for most building applications be of a self-extinguishing (SE) type, which is verified by a flammability test (Annex C).

IS 9091

: 2020

Expanded polystyrene (EPS) boards for thermal insulation - Specification

CurrentSpecializedSpecificationBIMArchitectural · Roofing Materials

Archive.org BIS Portal Google

This standard specifies the requirements, dimensions, sampling, and testing methods for expanded polystyrene (EPS) boards used for thermal insulation. It classifies EPS boards into different types based on physical properties like density and compressive strength, ensuring their performance for energy conservation in buildings and industrial applications like cold storage.

Specifies requirements for expanded polystyrene boards used for thermal insulation.

Quick Reference Values

Minimum Density (Normal Duty)15 kg/m³

Minimum Compressive Strength at 10% deformation (Normal Duty)60 kPa

Maximum Thermal Conductivity (Normal Duty)0.042 W/(m·K)

Maximum Water Absorption (by partial immersion)0.5 kg/m²

Dimensional Tolerance (Length/Width)± 2.0 mm

Dimensional Tolerance (Thickness)± 1.0 mm

Fire Performance RequirementMaterial shall be of self-extinguishing type

Practical Notes

Specify the correct density/type (e.g., Normal Duty, High Duty) based on the application's compressive load requirements (e.g., roof vs. wall).

Always specify and use the Self-Extinguishing (SE) grade for building envelope applications to comply with fire safety norms.

Protect boards from prolonged UV exposure (direct sunlight) and physical damage on-site to prevent surface degradation and maintain dimensional stability.