Preface

ABOUT THIS BOOK

Together with masonry, wood is the oldest construction material. From the dawn of time, wood structures have been built to provide shelter and religious spaces, to support manufacturing and commerce, and to form the (literal) underpinning for many forms of transportation. Wood is arguably the easiest construction material to work with and has the most pleasing appearance. It is no surprise that people have a natural affinity for exposed wood grain in their structures, including furniture.

Within this context, mass timber is not just a recent phenomenon, but also a logical extension of the wooden construction methods that have existed before it. While glulam construction was well known and used beforehand, the 1990s saw the emergence of a new material: Cross-Laminated Timber (CLT). The combination of those two materials, along with technological advances in digital fabrication, gave the wood-building industry the materials and tools to build larger, more commercial buildings and compete better with materials like steel or concrete. It is, however, largely due to the recent building code changes (e.g. the 2021 International Building Code in the United States) and a deeper understanding of the sustainability of our building materials that wood and specifically mass timber products are now considered as solutions for more and more building projects.

Many entities and institutions have paved the way for the acceptance of mass timber and are tirelessly engaged in facilitating its adoption. Universities and researchers have shown time and time again that the material is capable, efficient, safe, and comparable to other established materials. Knowledge has been exchanged in countless committees and at international conferences such as the biennial World Conference on Timber Engineering, or the annual Mass Timber Conference held in Portland, OR. Industry and other funding have enabled organizations like WoodWorks-Wood Products Council and the Softwood Lumber Board to exist and to promote wood structures in general and mass timber specifically in many ways - through free project support, publications, websites, workshops, and many other events. Likewise, associations like the American Wood Council and APA - The Engineered Wood Association have provided the standards-writing that enabled national model codes and state building codes to adopt their frameworks and provide the legal backing for this type of construction.

This book pays close heed to these developments. Our intention is to give all team members on a typical mass timber project a solid background in this topic. It is therefore not solely an architectural or engineering reference or a manual for wood construction. It was written with the goal of providing a foundation for all of these fields equally so that a basic, shared knowledge base can be established. As we will argue throughout the book, such background knowledge is critical for the success of a mass timber project and for the team behind it. The reader can then, with a sound footing, expand upon any one topic in any one area of the AEC (Architecture, Engineering, Construction) disciplines through the many excellent and current references available; or looking forward, through new project descriptions and various code and building material changes that the future will invariably bring with it.

Whether used in a university course, a studio project, or as a reference for structured self-study, this book provides all the required information for a student to ramp up quickly and understand key concepts of mass timber. It equips readers to solve real-world problems in a practice-oriented fashion. End-of-chapter questions and exercises, as well as a set of interactive companion exercises, provide many avenues to reflect on the presented material and to practice it.

The authors hope that the reader will find the text in this book engaging, the more than 650 figures and illustrations visually stimulating, and that they will take away many large concepts and big ideas that enable them to be productive participants on whichever mass timber project they set out to do.

BOOK ORGANIZATION

This book is organized into six parts that guide the reader from an introduction to mass timber and the various materials used in such buildings, through the planning process and design procedures, all the way to construction. At the end of the book, three case studies of key buildings serve to reinforce these topics and showcase different approaches to building in mass timber.

The chapters follow a natural progression, leading the reader from the fundamentals through application to implementation, mirroring the process that any mass timber project goes through. That said, it is also certainly possible for readers to focus on specific parts or chapters and use the book instead as a desk reference for topics of interest. For example, developers and designers who desire a "quick start" on mass timber may wish to begin their exploration with Part 3 (Chapters 7 and 8) and then delve deeper into the various topics as needed. Construction managers, on the other hand, may want to skip ahead to Part 5 (Chapters 14 and 15) right away.

Part 1 covers the evolution of wood construction and mass timber. A chapter on the history of wood construction puts the current mass timber construction types into their historical context. This is then followed by a chapter that addresses the sustainability aspects of wood construction, from the forest to the finished building.

Part 2 covers all the materials that underly mass timber construction, beginning with a chapter on wood. In that chapter, basic wood anatomy and behavior are discussed as well as durability and protection of the material. This is then followed by a chapter that takes wood from the tree to sawn products, which form the basis of all mass timber elements. A further chapter covers all the common mass timber materials such as glulam, CLT, nail-laminated timber (NLT), and others. A final chapter in this part discusses the many fastener types that are available for wood structures.

Part 3 provides the reader with a conceptual background for designing mass timber buildings. The current building code environment is presented, and many early-stage design concepts are discussed. This part covers all the crucial design decisions that need to be considered at the inception and early-design phases of a mass timber project to make it feasible, efficient, and budget-conscious.

Part 4 delves into the structural design of mass timber buildings, starting with a discussion of the code environment and its basic approaches. Chapters in this section cover in detail (with design examples) beams, panels, walls, and columns under gravity loads. Lateral force resisting systems are discussed in a subsequent chapter that presents concepts for both vertical as well as horizontal systems. A final chapter on the design of mass timber connections rounds out this part.

Part 5 features two chapters on the construction process for mass timber buildings. The first of those chapters concentrates on pre-construction aspects (design, contracts, estimating, and sourcing) while the second chapter discusses construction and on-site topics such as manufacturing, shipping, hoisting, erection, and protection of wood.

Three case studies at the end of the book present vignettes of three very different completed mass timber buildings: The John W. Olver Design Building is an example of an academic-use glulam post and beam frame with CLT flooring. The Brock Commons building is an example of a residential tall mass timber building that forgoes beams and uses only columns as well as CLT plates in a two-way spanning arrangement. The Origine apartment building is an example of a structure that uses CLT also for its bearing and shear walls. Even though these are not the most recent examples of successful mass timber projects, all of these buildings add many aspects to the discussion of mass timber, which makes them ideal showcase examples for the many paths a designer can take.

All chapters are thoroughly illustrated with many photographs that provide insights into the reality of mass timber design and construction as well as drawings that clarify the underlying concepts. End-of-chapter sections provide relevant web links and key references, which the reader is encouraged to peruse to dig deeper into any of the presented topics. A set of chapter review questions is offered to encourage self-study of the topics, while a set of hands-on exercises for a classroom or studio environment is also provided to help students reinforce topics within their own means.

INTERACTIVE EXERCISES

In addition to the book itself, Wiley's companion website at the following link features a collection of interactive exercises that allow the readers to use 3D modeling software to practice some of the covered principles, building assemblies, and construction techniques in the comfort of their home (or classroom). Doing this virtually in a 3D modeling environment removes the mess, waste, and safety requirements of doing the same as a physical laboratory exercise, while still retaining the educational benefits that come from completing such an exercise.

Learn more about these exercises and download them on this book's companion...