Stone is one of the oldest building materials, and its conservation ranks as one of the most challenging in the field. The use of alkoxysilanes in the conservation of stone can be traced as far back as 1861, when A. W. von Hoffman suggested their use for the deteriorating limestone on the Houses of Parliament in London. Alkoxysilane-based formulations have since become the material of choice for the consolidation of stone outdoors. This volume, the first to cover comprehensively alkoxysilanes in stone consolidation, synthesizes the subject's vast and extensive literature, which ranges from production of alkoxysilanes in the nineteenth century to the extensive contributions from sol-gel science in the 1980s and 90s. Included are a historical overview, an annotated bibliography, and discussions of the following topics: the chemistry and physics of alkoxysilanes and their gels; the influence of stone type; commercial and noncommercial formulations; practice; lab and field evaluation of service life; and recent developments. This book is designed for conservators, scientists, and preservation architects in the field of stone conservation and will also serve as an indispensable introduction to the subject for students of art conservation and historic preservation.