ÖNORM EN 13914-1

This document specifies requirements and recommendations for the design, preparation and application of cement, lime or other mineral binders, and/or combinations thereof, masonry cement and polymer modified binder based external renderings, on all common types of backgrounds, to both vertical walls and horizontal soffits. It includes rendering on both new and old backgrounds and the maintenance and repair of existing work. Renders with organic materials as the principal binder are not included in the scope of this document. This document gives guidance on the use of established site, factory and semi-finished factory made renders. NOTE 1 Because of the many and varied materials and practices in Europe it is not possible for certain aspects of the document to enter into sufficient detail to be fully usable to practitioners in each country. Such recommendations required to complement, but not alter any basic European recommendation are given in documentation prepared by each country. Aspects of this document which may need to be complemented are indicated where they occur by a footnote referencing this paragraph. Due to the wide range of climatic conditions in Europe, it is not possible to recommend precise drying times for backgrounds and render coats. Any times given are for guidance only. This document does not cover the following: a) the use and application of special renders for liquid retaining structures, e.g. coatings, and for backgrounds to cladding systems; b) the structural repair of concrete; c) the installation of proprietary external thermal insulation composite systems (ETICS); d) the specification and use of sealants used to seal joints for use with rendering; e) the use of gypsum based renders used externally, but their use may be permitted in some countries; NOTE 2 Gypsum based products soften when subject to prolonged moist conditions. The use of such products externally will depend upon the climatic conditions where the render will be used and on the local building traditions. With the exception of some drier countries in southern Europe gypsum based renders are generally not recommended for external use and are therefore not included within the scope of this document. Their use may be permitted and controlled locally2. f) the design and installation of flashings at windowsills and elsewhere. At various points in this document reference is made to the use of sealants. The specification of sealants and the design of such joints is outside the scope of this document.