External wall insulation
External Wall Insulation (EWI) systems, also known as ETICS (External Thermal Insulation Composite Systems), are suitable for both new and old buildings. Polyisocyanurate (PIR) insulation products, when used externally on solid wall constructions, offer one of the thinnest solutions available as a result of their superior thermal performance. By using these products, the energy efficiency of a building can be easily and economically improved without sacrificing valuable internal floor area.
External wall insulation is used as part of a system designed by a designated EWI System Designer whose primary role is to design, manufacture and supply certified external wall insulation systems in a range of insulation materials and finishes to meet the needs of the UK, European and Worldwide Markets.
When PIR insulation products are used they are mechanically fixed to an existing wall behind a traditional or lightweight polymer modified render system or fixed behind timber counter battens behind rendered expanded metal/cement board.
Key benefits of EWI render systems include:
- Improved aesthetic
- Improved energy performance
- Extended serviceable life of a building External Wall Insulation is often the logical choice for improving the thermal performance and external façade of an existing or new building, and is especially popular for high-rise buildings.
Man-made-mineral-fibre (MMMF) is susceptible to water penetration and this can have a severe effect on its thermal performance. PIR/PUR insulation products are resistant to moisture penetration, as a result of their closed cell structure. Consequently the thermal performance of PIR/PUR insulation products should remain at its designed level for the lifetime of the building.
Benefits of PIR/PUR insulation for External Applications:
Superior thermal performance;
- Minimal cold bridging;
- Does not settle and leave part of the wall un-insulated;
- Constant thermal performance for lifetime of the building;
- Eliminates the risk of water penetration;
- Are resistant to moisture ingress;
- Are non-fibrous and do not emit harmful emissions;
- Does not support the growth of fungi.
IMA has developed a Best Practice Guide looking at the installation of External Wall Insulation which is available here and should be used in conjunction with the advice and recommendations of the system designer.