What is the primary indicator of insulation performance in this standard?

Thermal conductivity (k-value). A lower value means better insulation. See Clause 5.4 and Table 4.

Is mineral wool specified under this code fireproof?

The material itself is classified as 'Non-combustible' as per Clause 5.7, when tested according to IS 3808. The overall fire rating of an assembly depends on all components.

What are the different forms of mineral wool covered by IS 12435?

It covers bonded slabs, lamella (slabs with fibres perpendicular to the face), pre-formed pipe sections, and blankets (Clause 4).

Does this standard cover installation procedures?

No, IS 12435 is a material specification. Installation is covered in other codes of practice, like the National Building Code (NBC).

IS 12435

: 2022

Mineral wool thermal insulation materials - Specification

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This standard specifies the requirements, testing methods, and sampling for factory-made mineral wool products (including rock wool and slag wool) supplied as slabs, blankets, and pipe sections. It is primarily used for thermal and acoustic insulation in buildings and industrial applications.

Specifies requirements for mineral wool (rock wool and slag wool) thermal insulation materials.

Quick Reference Values

Maximum Thermal Conductivity at 25°C0.046 W/(m.K) (varies with product type)

Nominal Density Range25 kg/m³ to 200 kg/m³

Maximum Service TemperatureUp to 750 °C (for unfaced products)

Reaction to Fire ClassificationMaterial is Non-combustible

Maximum Water Vapour AbsorptionNot more than 1.0 percent by volume

Maximum Shot Content by Mass15 to 25 percent (varies with density)

Practical Notes

Ensure the correct density is specified; higher density for compressive strength (e.g., roof insulation), lower density for cavity walls or acoustic panels.

Mineral wool's performance can be degraded by moisture. Ensure proper weather/vapour barriers are used in the assembly.

Always check the marking on the packaging for conformity to IS 12435, including density, dimensions, and thermal conductivity group.