Читать книгу Monument Future - Siegfried Siegesmund - Страница 83

In the Vexin Français area, 40 to 70 km NW from Paris, two principal construction techniques are found: important buildings (churches, chateaux or big houses) are built in ashlar masonry, whereas smaller ones (farms, houses and other vernacular buildings) are made on random rubble masonry covered by renders. Nowadays many new owners of traditional buildings want to remove renders in order to show the stone masonry. This new tendency has two major disadvantages: it alters region landscape and it exposes masonry to weathering and decay induced by environmental conditions.

The long-term goal of the study is to provide proofs that traditional renders are much more adequate and durable when repairing stone façades than new cement base renders. Most of the façades in the Vexin area are made of rubble stones with a lime mortar and covered by a plaster of Paris, lime or plaster of Paris-lime render. The use of this kind of render has aesthetic purposes, helps to evacuate the humidity and has a protection role.

Our study focused on comparisons between ancient renders sampled in façades of the Vexin area and new formulations of renders supplied by Plâtrière Vieujot. This society has been producing plaster of Paris renders since 1880. One of its renders, “plâtre Briard” is used in rural areas of Paris region as external render 66because of its non-uniform aspect due to the presence of impurities like charcoal and small pieces of gypsum stone.