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IS 12436:1988 is the Indian Standard (BIS) for rigid polyurethane (pu) foam for thermal insulation. This Indian Standard specifies the requirements, testing methods, and sampling procedures for rigid polyurethane (PU) foam intended for use as thermal insulation. It covers essential physical properties such as density, thermal conductivity, compressive strength, and dimensional stability to ensure material quality for applications like cold storage and building insulation.
Specifies requirements for rigid polyurethane (PU) foam used for thermal insulation.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
Practical Notes
! This standard is critical for Quality Assurance (QA) of insulation material on-site or at the factory. Always ask for a manufacturer's test certificate referencing IS 12436.
! The 'closed cell content' is a key parameter for long-term performance, as high open-cell content can lead to moisture absorption and degradation of thermal resistance.
! While the standard was published in 1988, it has been reaffirmed multiple times (e.g., 2004, 2014, 2019), indicating it is still the current and valid specification in the absence of a newer version.
Provides a framework for specifying rigid cellular plastics, including PU, for building insulation.
BS EN 13165:2012+A2:2016BSI (British Standards Institution), UK
HighCurrent
Thermal insulation products for buildings. Factory made rigid polyurethane foam (PU) products. Specification
The British adoption of the European standard, essentially identical in technical content to EN 13165.
Key Differences
≠IS 12436 classifies products into three types based on density, whereas modern standards like EN 13165 use a designation code system based on declared performance levels for various properties (e.g., compressive strength, thermal resistance).
≠The Indian standard specifies thermal conductivity 'at the time of manufacture'. International standards like EN 13165 and ASTM C591 mandate the declaration of an 'aged' thermal conductivity value, which accounts for the gradual diffusion of insulating gases and provides a more realistic long-term performance figure.
≠Fire performance in IS 12436 is evaluated by a simple 'Extent of Burn' test. In contrast, EN 13165 references the comprehensive Euroclass system (EN 13501-1), which classifies products from A1 to F and includes assessments of smoke production and flaming droplets.
≠The Indian standard is dated 1988 and has only been reaffirmed, while the international equivalents are actively and frequently updated to reflect new test methods, safety requirements (e.g., blowing agents), and performance models.
Key Similarities
≈All standards are fundamentally specifications for factory-made rigid cellular plastic foam intended for thermal insulation in building and industrial applications.
≈They all specify requirements for a core set of physical properties, including thermal conductivity, density, compressive strength, dimensional stability, and water absorption.
≈The minimum requirement for closed cell content is consistently high across the standards (typically ≥90%), as this is critical for the material's insulating performance and moisture resistance.
≈All standards specify test methods for each property, either by referencing other specific standard test methods (e.g., ISO or ASTM test methods) or by defining the method within the standard itself.
Parameter Comparison
Parameter
IS Value
International
Source
Thermal Conductivity (k-value)
Max 0.02 W/m.K (at 10°C mean, unaged)
Typically 0.022 W/m.K (declared aged value λD at 10°C mean)
EN 13165
Classification Basis
Density-based (e.g., Type 2 = 36 ± 4 kg/m³)
Performance-based (e.g., CS(10\Y)150 for compressive strength)
EN 13165
Compressive Strength (at 10% deformation)
Min 147 kPa (for Type 2)
Declared level, e.g., CS(10\Y)150 = Min 150 kPa
EN 13165
Closed Cell Content
Min 90%
Min 90%
ASTM C591
Dimensional Stability (at low temp)
Max 1% change (24h at -30°C)
Max 2% linear change (7 days at -29°C)
ASTM C591
Water Absorption (by partial immersion)
Max 0.2 kg/m²
Levels defined, e.g., WS(P)0.2 = ≤ 0.2 kg/m²
EN 13165
⚠ Verify details from original standards before use
Key Values5
Quick Reference Values
Maximum Thermal Conductivity (Initial)0.029 W/(m.K)
Minimum Closed Cell Content90 %
Minimum Compressive Strength at 10% deformation1.5 kgf/cm²
Maximum Water Vapour Permeability4.0 perms-cm
Nominal Density Range32 to 60 kg/m³
Tables & Referenced Sections
Key Tables
Table 1 - Physical Requirements of Rigid Polyurethane Foam
What is the most important property for PU foam insulation according to this standard?+
Thermal conductivity. The standard specifies a maximum initial value of 0.029 W/(m.K) as per Table 1, which is the primary measure of its insulation capability.
What are the standard density classes for PU foam in IS 12436?+
The standard specifies nominal densities such as 32, 40, 48, and 60 kg/m³, with an allowable tolerance of ±3 kg/m³ (Clause 4.1.1).
How is compressive strength measured?+
It's measured at 10 percent deformation in a direction parallel to foam rise. For a 32 kg/m³ density foam, the minimum strength required is 1.5 kgf/cm² (Table 1).
Does this standard cover fire safety aspects?+
It references IS 11239 (Part 3) for the test method for surface burning characteristics but does not set specific limits, stating they shall be as agreed between the purchaser and the supplier (Clause 5.7).