Conservation practitioners have long recognized the importance of using limes in repairing historic buildings. But research into the application of limes over the past twenty years has revealed that many of our assumptions about how limes were used historically may well be over-simplistic or even wrong. This book brings together a selection of the best material, revised and updated, which first appeared in the Journal of Architectural Conservation and in the Journal of the Building Limes Forum. The very useful Introduction traces developments in lime-based materials, including the establishment of hydraulic limes into the market and the decline in the use of Portland cement for conservation work. Part 1 focuses on understanding the nature and origins of lime and lime based mortars, including hydraulic lime and Roman cements. Part 2 covers research and analysis of lime materials with investigations into the current standards for their use. Part 3 examines the techniques that were used historically and how these can be applied today, offering examples from current practice. These include the use of hot lime mortars and recent material on nano-lime.Architects, conservation practitioners, construction historians and those researching developments in lime will find this an informative and useful source of reference.