Excerpt from A Treatise on the Design and Construction of Roofs Fourteen years' experience with the State examinations for license to practise architecture in Illinois has clearly shown that applicants are usually able to determine the stresses in the members of roof trusses, but are frequently unable to dimension them accordingly or to connect them properly at the apexes of the trusses. The necessary formulas and data are scattered in numerous reference works, and their selection and exact application require more time than is allowed to the busy architect or engineer. Therefore the purpose of the present work is to supply the data, methods, formulas, and tables required in the design of a roof, arranged in the simplest manner and so as to require the least time and labor in their application. Many years spent in the instruction of students have shown the author that the study of a series of selected and fully solved examples is more useful in the training of the student than the mere memorizing of many rules and much good advice without frequent applications to practical cases. Twenty-five examples of roofs are treated in successive chapters, each chapter being confined to a single stage in the process, such as determining stresses, dimensioning members and detailing connections, estimating weights of trusses, etc. Only the methods of graphostatics required for roof trusses are first given, followed by a description of the parts of wooden and steel roofs, succeeded by the data and formulas required for computing loads on roofs. New formulas are given for the approximate weights of roof trusses, based on the careful design and calculation of numerous examples. It may surprise some readers to learn that steel trusses may be safely designed considerably lighter than those chiefly constructed of wood. An original formula is given for weight of snow, applicable to the United States, excepting the Pacific States. A simple formula for wind pressure must suffice until the actual conditions have been determined by extended experiments and research. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.