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EXHIBIT “C” - Appendix “C” <br />Assessing the Extent of Decay <br /> <br /> <br />Decay is a critical factor in the stability of the tree, and therefore in hazard <br />evaluation. Specific characteristics of the trunk and canopy, as well as site <br />conditions and management history conditions can indicate the potential for <br />decay. The evaluator should look for: <br /> <br />1. wounds, cavities, dead and broken branches; <br />2. fruiting bodies of decay fungi (conks, bracts, mushrooms); <br />3. bleeding (oozing sap) through the bark; <br />4. borers, carpenter ants, termites; <br />5. nesting holes, bee hives; <br />6. seams, woundwood formation; <br />7. sloughing, cracked bark, change in bark texture; <br />8. site change, root injury, change in grade; <br />9. poor soil drainage, ponding, heavy irrigation; <br />10. intense and repeated pruning; <br />11. History of failure. <br /> <br />If decay indicators are present, the extent of decay should be evaluated. <br />Methods include: <br /> <br />1. striking with mallet and listen for changes in tone <br />2. probing into exposed decay <br />3. exploratory digging when root rot is indicated <br />4. drilling to determine color, odor, penetration resistance, and extent of <br />decay. <br /> <br />We rely most heavily on sounding to help locate major hollows, then drilling <br />suspected areas with a 1/8” bit that is 10” long. The drill is pushed into the <br />tree about 1-2 “and removed. The extracted wood is removed from the bit and <br />examined. This is repeated until the appropriate sampling depth is reached. In <br />this way the how much sound wood is present can be estimated. <br /> <br />When determining the number and location of borings, the inspector should <br />estimate the size and conformation of the decay column based on external <br />signs. Then drill to establish the limits of the column. Just as too many <br />borings should be avoided, so should too few. Drilling in two or three places <br />at one level on the trunk provides information at those sample locations only. <br />It will not identify potential problems in the root crown, lower or higher on the <br />trunk, or at branch attachments. <br /> <br />564