Throughout history, wherever wood has been available as a resource, it has found favor as a building material for its strength, economy, workability and beauty, and its ability to last has been demonstrated again and again. From the ancient temples of Japan and China and the great stave churches of Norway to the countless North American and European buildings built in the 1800s, wood construction has proven it can stand the test of time. The art and technology of wood building, however, has been changing through time.
It’s a common misconception that water is wood’s enemy. That’s not necessarily true, since many wood buildings exist in rainy and humid places. It’s a matter of knowing how to manage water in buildings. Protection of buildings from water is the important design criterion, as important as protection from fire or structural collapse. Designers, builders and owners are gaining a deeper appreciation for the function of the building envelope (exterior walls and roof). This includes the performance of windows, doors, siding, sheathing membranes, air and vapour barriers, sheathing, and framing. The capabilities and characteristics of wood and other construction materials must be understood, and then articulated in the design of buildings, if proper and durable construction is to be assured. Wood and water are typically very compatible. Wood can absorb and release large quantities of moisture without problems, and it’s only when wood gets too wet for too long that there may be problems. If buildings are properly constructed to shed water, wood performs well as a building material in all types of climates. As an example, 90% of North American homes are built with wood. The primary focus of this publication is to address the control of rainwater penetration in exterior walls, which is the major source of moisture issues for all building materials, particularly in climates subject to high rainfall.
