External rendered finishes.
THIS PUBLICATION HAS BEEN ARCHIVED.
Whilst this publication can still be purchased some of the information in it has been superseded by more recent research and standards. The BRE Group does not accept any responsibility whatsoever for any loss or damage, including - without limitation - indirect or consequential loss or damage arising from use, or loss of use, of data or profits arising out of, or in connection with, the use of this document.
National Building Studies Bulletin no. 10 is a comprehensive guide to the design, application, performance and repair of external renderings and a British Standard code of practice on the subject is in course of publication [BS 5262:1976]. Defects are still common, however, and inspection usually reveals that they result from some transgression of basic principles. These notes are therefore intended to re-emphasize a few main points with particular reference to new work where a rendering is applied for its appearance or to resist rain penetration.
The use of design details, such as wide eaves, to reduce the amount of rain falling on a wall, is recommended. Mixes for external rendering should be appropriate for the exposure conditions and are listed in a table. Proprietary mixes and aerated ('plasticized') mortars are also discussed.