3.1.1 - Le principali forme di degradamento del legno

One of the objectives, in the modern methodological approach of the wood technology, is to attribute to each element its current carrying capacity and to assess its effective section, which means the part of the cross section which is assumed to carry the load. The principles of application are reported in the Italian standard UNI 11119:2004. Under ideal conditions wood can be running for centuries without undergoing significant changes but, like all other biological materials, if the environmental parameters become favorable to a biotic or an abiotic alteration, wood properties can decrease during the service life. Among the causes of abiotic alteration there is the reduced load-carrying capacity due to a high stress level, continued for a long time. In fact some wooden elements were very flexed during the centuries and cracks were visible in the roof.