External Thermal Insulation Composite Systems (ETICS)
There are many external thermal insulation (ETI) techniques:
- Beneath coating
- Beneath external cladding
- Directly-applied insulated cladding panels...
All these techniques have an impact on the properties of the exterior wall (weatherproofing, wind resistance, fire safety, durability, appearance, etc.), and therefore require specific expertise. A number of best practice guides are available, and in the great majority of cases, the processes concerned are covered by a Technical Assessment or Technical Application Document (DTA).
In case of ETICS with insulation beneath coating, there are a number of issues requiring close attention to detail:
- the type of wall construction
- the type of insulation fixing: bonding or mechanical fixing
- the coating system used to cover the insulation
- the interactive compatibility of all these components
The system as a unit must comply with the many requirements detailed in the DTA for each process. The insulation material itself is subject to a minimum set of characteristics that make it suitable for use beneath coating. These characteristics are key to the durability of the total system by limiting the risk of facade defects or compromised weatherproofing, which could affect the external appearance of the building over time.
The following minimum ISOLE profile applies to expanded polystyrene insulation materials for bonding or mechanical fixing using appropriate anchors:
The following minimum ISOLE profile applies to expanded polystyrene insulation materials for mechanical fixing using profiles (excluding. grey polystyrene):
The minimum characteristics for other types of insulation are given on a case-by-case basis in the individual DTA for the process concerned.
Lastly, particularly close attention should be paid to the many points of detail raised by (geometry, joints, window frames, etc.) to ensure optimum performance of the system used, limit thermal bridging and minimize any faults appearing in the facade.
For more information
- CSTB Guides
- from bookshops or to order from boutique.cstb.fr
- RAGE Guides
- CCFAT WebSite
- www.ccfat.fr : the Commission Chargée de formuler les Avis Techniques (CCFAT) website and the Cahiers des Prescriptions Techniques (CPT) editorial team