I have heard the term "wood pathologist" used by architects, engineers and lawyers for years. I've personally never put any thought into the title until recently. I did some searching on the internet and found very little information for "wood pathology" except for one website, the Wood Products Pathology and Preservatives Chemistry Laboratory. That laboratory, coincidentally, is where I did a lot of my graduate research while studying Wood Science and Engineering at Oregon State University. However, other than that site, there really isn't much information on 'wood pathology', so I've decided to write about my views associated with it, particularly as it pertains to assessing structures. The first step is to define wood pathology and then determine a general job description for a consulting wood pathologist.
The following are some exemplar definitions of pathology:
- "the science of causes and effects of diseases, especially the branch of medicine that deals with the laboratory examination of samples of body tissue for diagnostic or forensic purposes."
- "the study of diseases and changes they cause."
- "the study of the essential nature of diseases and especially of the structural and functional changes produced by them."
Based on my experience in the field of wood science and engineering as well as 18 years of consulting, I would define wood pathology, especially as it pertains to structural purposes, as follows:
Wood Pathology: the investigation and forensic study of the wood and wood-based elements in structures to determine their structural integrity, especially that which is affected by wood destroying organisms (i.e. wood decay, insects, marine borers, etc) or chemicals.
In my opinion a wood pathologist should be able to perform the following functions when assessing a structure:
- Determine the visual grade of lumber and timbers for allowable properties
- Assess glulam beams and other structural composite lumber
- Determine the wood species of the various elements in the structure
- Document any areas exhibiting any type of deterioration or mechanical damage
- Perform microbiological analyses for the assessment of wood decay
- Evaluate current preservative retention levels, as needed
- Perform non-destructive testing, as needed
- Perform destructive testing, as needed
- Provide the client with a complete diagnosis and recommendations (i.e. usually current allowable design values)
If you have a structure that requires a wood pathologist, feel free to contact Wood Science Consulting with any specific questions or concerns.