Tiles and Architectural Ceramics Society - This UK society provides a beginner's guide to the history of tiles used pave floors or decorate walls. Azulejos de Lisboa - Colin Manning gives a photographic tour of some of the Portuguese tiles, known as azulejos, which adorn the inside and outside of almost every home in Portugal. Timeline of Concrete - The story of concrete from the natural deposit of cement compounds 12,000,000 BC, through the creation of concrete by the Romans to its uses in the 1990s. Short bibliography. Roman Concrete - David Moore's writings and references on Roman and modern concrete technology and construction. Stone Roofing Association - Provides an introduction to sandstone and limestone roofs, giving the geology, history and use of stone slates, with bibliography and glossary. The Traditional Paint Forum - A non-profit group with an interest in historic decorative schemes, which publishes the journal "Traditional Paint News" (contents listed online). Annual conference, membership, news. Old Cast Iron - History of cast and wrought iron architecture between 1850 and 1920. Articles with information and pictures. Some articles are brought with prior permission from authorities on the topic.