This report describes how lumber can be air-dried most effectively under outdoor conditions and illustrates the principles and procedures of air-drying lumber that were developed through field investigations and observations of industrial practices. Particular emphasis is placed on the yarding of lumber in unit packages. Included are topics such as why lumber is dried, advantages and limitations of the drying process, properties of wood in relation to drying, layout of the drying yard, piling methods, causes and remedies of air-drying defects, and protection of air-dried lumber.

Drying Hardwood Lumber focuses on common methods for drying lumber of different thickness, with minimal drying defects, for high quality applications. This manual also includes predrying treatments that, when part of an overall quality-oriented drying system, reduce defects and improve drying quality, especially of oak lumber. Special attention is given to drying white wood, such as hard maple and ash, without sticker shadow or other discoloration. Several special drying methods, such as solar drying, are described, and proper techniques for storing dried lumber are discussed. Suggestions are provided for ways to economize on drying costs by reducing drying time and energy demands when feasible. Each chapter is accompanied by a list of references. Some references are cited in the chapter; others are listed as additional sources of information.

At present, no single book adequately covers a basic understanding of wood book satisfies the need for such a work. It describes drying in practice. This the fundamental basis of kiln-drying technology, to enable forest companies to imFrove their drying operations as high-quality timbers become scarcer and of yesteryear can no longer be tolerated. Adaptive the wasteful practices is no longer good enough. Innovations change based on past experience of the material being dried and the processes require a sound understanding of drying. Newer techniques, such as the use of ultrahigh temperature sea soning and superheated steam under vacuum, require an even greater depth of physical understanding for these methods to be used effectively and economically. book provides a description of modern ideas about wood structure, This moisture movement and stress development, from which models of the drying process are developed to give the kiln operator important information about the course of drying under specified conditions, and thus a means is compared with practice wherever for rational process improvement. Theory possible.