The Essential Timber Guide

Introduction

With such a great natural resource available for so many different applications it is only sensible that the timber be used correctly and efficiently and that the resource not be wasted. To achieve this it is essential that users understand the product and that architects and timber designers also be knowledgeable on the many technical implications involved in the use of timber. They are then better equipped to ensure success in the multitude projects they work on. This list of projects in which timber can be used is immense. For example, it can range from major structures through to domestic housing and associated items such as floors, decks and other outdoor structures. Another large use of timber is in furniture manufacture and it is regularly used in craft activities like wood turning.

The purpose in writing this book, after encouragement from a well-known Central Queensland architect, was to commit to written form timber information the author had been fortunate to acquire through formal education and many years experience in different roles in the industry. Firstly, it would be interesting and helpful to users of timber and also those involved in the design phase. Secondly, it would, by providing essential information, help ensure timber and associated board products are used correctly and so help prevent problems occurring. Thirdly, as others gradually succeed the current small group of people highly qualified in timber technology, it would be an added source of technical information. The current small group provdes an essential service to the industry at large by providing information to designers and users, investigating site timber problems when they occur, preparing explanatory literature, assisting in the development of new standards, plus many more technical needs. In writing this book, it also became apparent that many critical sections where specific essential information was needed had to be covered. One example of this is the relationship of timber with moisture and the many aspects of this relationship. There are also several other critical sections that needed to be included. Thus, the original intent of the book, that it just be an interesting read for designers and users, was changed so that all this critical and essential information is covered. Hence the title . It is hoped by careful study of relevant sections and frequent reference to the book that it will go a long way to achieving the efficient and correct use of timber.

By studying timber from the aspect of cell structure an explanation of many properties of timber becomes apparent. In particular the close relationship between timber and moisture becomes clear. Also, it gives an insight into why different species have different properties such as differences in decay resistance and resistance to termites and insects. An endeavour is made to not only provide the necessary factual information but also explain the reason why.

While much information about timber can be found by accessing the internet it is only as uncoordinated pieces of information. However, in studying the book all the information is grouped together so that it is easy in reading it to pass from one subject to associated subjects. While the book is essentially a ‘textbook’ every effort has been made to not write in typical textbook style. The book has been written in simple understandable free flowing language illustrated with plenty of photographs and a number of diagrams. The purpose in doing this was to make it easily understood and try and ensure that as wide a range of timber users as possible might be able to easily comprehend all the subjects covered. The great majority of all the photographs were taken by the author. For copyright reasons the source of other photographs and the diagrams have to have the approval of the company or person responsible. This has proved to be extremely difficult as many of the companies and people no longer exist. Where possible this approval has been secured.

Over recent years many changes have occurred in the timber industry. One of these has been a change in methods of marketing. Once timber was only available from timber merchants with staff specially trained in timber knowledge to disseminate information about timber. While timber merchants with staff trained in timber knowledge still operate, the current situation is that much of timber is now being mass merchandised with few people on hand with timber knowledge. The book therefore serves another useful purpose. If the buyer is unsure of what timber or species to purchase reference to the relevant section in the book can certainly help. The appendix is useful in this regard as it lists a wide range of different timbers with the different properties of each.

However, while the above comments are pertinent the author freely acknowledges that many architects, designers and builders have acquired a wide range of essential knowledge about timber over many years so they have little trouble in specification or purchasing the correct timber for the specific applications. However, it is still possible that some sections of the book can add further to their knowledge.

While access to essential knowledge is essential in the successful use of timber it is the author’s opinion that this concept basically applies to all types of human endeavour. With this knowledge the necessary planning can be then carried out to enable projects to proceed. Whether it be putting a man on the moon or constructing major works like dams, bridges and skyscrapers. The key to all this is having easy accessibility to all of this relevant essential knowledge and then using it. Many of the major catastrophes that have occurred over the years have resulted from not having this essential knowledge or intentionally or unintentionally not using it. Failure of many bridges around the world, fires in the facades of high-rise buildings, collapse of multistory buildings in some countries, failure of tailing dam walls associated with mining operations are just a few examples in recent years. Many of these resulted in considerable loss of life. It is still happening. Needless to say the timber construction has not been immune to construction problems but generally without such dire consequences. For the interest of readers a few case studies of where timber problems have occurred have been included in Chapter 11.

Some 50 years ago the Department of Forestry in NSW realized that due to lack of information designers and users were not capitalizing on the availability of the great range of excellent NSW hardwoods available. One of their officers, Keith Bootle, who had a great depth of timber knowledge was commissioned to produce a book giving the necessary information. As well as information on NSW hardwoods, Keith also took the opportunity to include a lot of other information in the book including technical information about timber. This book served a real need and was widely read. The book was revised some 17 years ago. However, progress in the timber industry continues and there have been many important developments since then as for example cross laminated timber, changes in milling practices and new or revised Australian standards.

In producing the Essential Guide a somewhat different approach to that adopted in the NSW Forestry publication has been taken. As mentioned previously considerable importance is placed on the how much the cell structure of timber is integrated into so many of the properties of timber. Readers are encouraged to study the text so they not only have access to all of the various properties of timber but also understand the reason ‘why.’ The guide also includes chapters on the range of board products especially plywood and veneers, glue laminated products and also a chapter devoted to working with timber. In short, the Essential Guide is quite different in many ways from the excellent NSW Forestry publication that was produced many years ago. It is also intended that it be equally suitable for use in any Australian state.

The author was encouraged to put this book together by a well-known central Queensland architect Mr. Brian Hooper. Mr. Hooper won awards for the design of a well-known timber structure in Barcaldine in central Queensland called the Tree of Knowledge. Because there are some 3600 pieces 125mm x 125mm pieces of hardwood hanging from supports above and the public are free to walk underneath there was a real need to check for any dangerous splits and checks particularly around the support points that could cause these very heavy pieces of timber to drop. On one of the early visits to the site with Mr. Hooper the author to his surprise found himself explaining all kinds of basic terms and technical details about timber that he thought most architects knew. He was assured this was not the case and he felt that many of his associates were in the same position. He suggested that, as he felt the author had acquired considerable knowledge on this subject, he commit it to writing in the form of a book.

This discussion then also helped the author better understand after carrying out hundreds of on-site inspections over many years throughout Queensland and in northern New South Wales why timber problems had arisen. These requests emanated from a wide range of sources particularly Government Building authorities who are the usual arbiters when disputes arise. The reason why problems occurred was that, in spite of the best of intents, the architect, designer or builder did not have enough of an understanding of the properties of timber or the recommended procedures for the project in hand. In providing all this essential information in an easily readable book for all to use, it is hoped it will provide a quick handy source of this essential information.

In setting about the project, it was realized that with the great diversity of subjects and the sheer amount of information involved, no one person would be adequately qualified and that a lot of help would be needed. This has been freely supplied and has come from a wide range of sources including Australia’s major millers, foresters, specialists in the timber industry, timber industry associations and major machinery manufacturers. When considering the many uses of timber, it is also considered important that the community at large look favourably on using timber as a construction material rather than steel or concrete particularly as timber is a renewable resource. In addition, by so doing they also ensure the health of the timber industry which is a major contributor to Australia’s economy. This favourable perception by the community depends very much on the correct use of timber in its many applications. This in turn depends on the designer, the builder, the user and the timber supplier having a thorough understanding of timber and its many properties. Hopefully in some small way the Essential Guide can make a contribution.

Lastly great care and attention has been taken that as far as possible what has been written is correct and to this end the author is indebted to a number of highly qualified people in the timber industry for checking various sections of the subjects covered.