ISO 12575-1:2012

Overview

ISO 12575-1:2012 - "Thermal insulation products - Exterior insulating systems for foundations - Part 1: Material specification" defines the basic performance and testing requirements for thermal insulation materials used on the exterior of foundations and slabs where the insulation is in direct contact with ground soils. It excludes systems for foundations permanently immersed in water. The standard guides designers, manufacturers and installers on what material properties must be declared and tested to ensure durable, fit-for-purpose foundation insulation.

Key topics and requirements

• Scope and applications: Covers four application types - frost (ground) insulation, perimeter insulation, non‑load‑bearing under‑slab insulation, and load‑bearing insulation - each with specific declared properties.
• Mandatory performance parameters:
  • Thermal conductivity (declared per ISO 8301 or ISO 8302; mean temperatures 27 °C, 23 °C, or 10 °C).
  • Compressive stress (declared and tested per ISO 29469).
  • Long‑term water absorption (ISO 2896).
  • Compressive creep for load‑bearing use (ISO 20392); thickness reduction for load bearing shall not exceed 2% initially, and extrapolated 50‑year reduction shall not exceed 5%.
• Optional parameters (specified when required by designer or national rules):
  • Water absorption by diffusion (ISO 20393)
  • Freeze–thaw effects on water absorption and compressive strength (ISO 20394)
  • Fungi/biological resistance (ISO 846)
• Testing and conditioning: Sampling, conditioning and test procedures are defined. Typical conditioning environments include (23 ± 2) °C & (50 ± 5)% RH (or specified alternatives) for a minimum of 48 hours.
• Declaration and documentation: Manufacturers must declare values, comply with applicable material standards and national regulations, provide test reports and label the product accordingly.

Practical applications

• Use this standard when specifying or selecting exterior foundation insulation to control heat loss, prevent frost heave, or provide load‑bearing thermal layers beneath slabs.
• Typical use cases: shallow or full basements, perimeter wall insulation, insulated footings, and exterior edge insulation for slabs.
• It helps ensure long‑term thermal performance, mechanical stability under soil loads, and resistance to moisture and freeze‑thaw where required.

Who should use ISO 12575-1

• Specifiers, architects and engineers designing foundation insulation systems.
• Manufacturers of rigid cellular plastics and other foundation insulation products for product specification and labeling.
• Test laboratories performing thermal, mechanical and durability tests.
• Installers and contractors, in conjunction with ISO 12575-2, to meet installation and compliance requirements.
• Regulators and building authorities assessing compliance with national application requirements.

Related standards

• ISO 12575-2 (installer responsibilities)
• ISO 8301 / ISO 8302 (thermal conductivity)
• ISO 10456 (declaration of thermal values)
• ISO 2896, ISO 20393, ISO 20394, ISO 20392, ISO 29469, ISO 846 (water absorption, creep, freeze‑thaw, biological resistance)

Keywords: ISO 12575-1, thermal insulation, exterior insulating systems for foundations, foundation insulation, perimeter insulation, load-bearing insulation, thermal conductivity, compressive creep, water absorption.