Abstract

There are numerous biological degradations that wood is exposed to in various environments. Biological damage occurs when a log, sawn product, or final product is not stored, handled, or designed properly. Biological organisms such as bacteria, mold, stain, decay fungi, insects, and marine borers depend heavily on temperature and moisture conditions to grow. Figure 5.1 gives the climate index for decay hazard for the United States of America. The higher the number means a greater decay hazard. The southeastern and northwest coasts have the greatest potential, and the southwest has the lowest potential for decay. This chapter will first focus on the biological organisms and their mechanism of degradation, and then prevention measures. If degradation cannot be controlled by design or exposure conditions, then protection with preservatives is warranted.