ETAG 034 Edition July 2011 GUIDELINE FOR EUROPEAN ...

3.2.8 Air spaceSpace between the cladding and the insulation layer or substrate accordingly.3.2.9 Ventilated air spaceA layer of air between the substrate or insulation layer and cladding elements connected to theexternal environment permitting water vapour diffusion from the internal side of the wall.External wall claddings are considered as ventilated when the following criteria are fulfilled :• The distance between the cladding elements and the insulation layer or the substrateaccordingly (ventilation air space) amounts to at least 20 mm. This air space may bereduced locally to 5 to 10 mm depending on the cladding and the subframe, providedthat it is verified that it does not affect the draining and/or ventilation function,• Ventilation openings are envisaged, as a minimum, at the building base point and atthe roof edge with cross-sections of at least 50 cm 2 per linear metre.3.2.10 Breather membraneMembrane placed in the cladding kit which contributes to the watertightness of the wall.ETAG 03418