Deterioration of an in-service wood member may result from a variety of causes during the life of a structure. Periodic inspection of wood used in structures is important for determining the extent of deterioration so that degraded members may be replaced or repaired to avoid structural failure.
Inspection professionals use a wide variety of techniques to assess the condition of wood in service. Visual, mechanical probing, and stress wave or ultrasound-based techniques are all used either individually or in combination by inspectors. Although these techniques are based on solid technical information and supporting research, prior to publication of the Wood and Timber Condition Assessment Manual in 2004, no practical, comprehensive manual provided information on inspection of wood in service.
According to editor and Supervisory Research General Engineer Robert J. Ross “The Wood and Condition Assessment Manual was prepared to address this need. The manual was prepared from numerous research studies, inspections, and lectures dealing with assessing the condition of in-service wood and timber. It was intended for inspection professionals. A concerted effort was made to provide clear and concise explanations of various aspects of inspecting in-service wood and timber. To this end, a number of photographs and drawings obtained from actual inspections were included.”
Ross goes on to say, “In preparing this second edition of the Wood and Timber Condition Assessment Manual, I had three objectives: (1) to update the existing chapters to reflect advancements in inspection methods; (2) to develop new material that focuses on a wide range of new techniques and technologies that have been investigated for use in assessing the condition of wood structures and provide estimates of the properties of in-service wood; and (3) to make the manual available in digital format.”
The newly published and comprehensive Wood and Condition Assessment Manual summarizes information on condition assessment of in-service wood, including visual inspection of wood and timbers, use of ultrasound and probing/boring techniques for inspection, and assessment of wood and timbers that have been exposed to fire. The report also includes information on assigning allowable design values for in-service wood.
The Wood and Timber Condition Assessment Manual—Second Edition is available in digital format from the Forest Products Laboratory website.