Um Holz und Bekämpfung seiner Schädlinge
Wood is a material with very usefull qualities, which can be further modified or enhanced by various means. It has been extensively used in civil engineering since the ancient history, especially for roof-bearing constructions (trusses). Peaple have gradually gained knowledge in efficient truss design, construction methods and in wood conservation, so that a well-built and well-maintained wooden truss could last even for multiple centuries.
The universality of use of wood for construction purposes is indicated by the fact, that it is being used all over the globe, at all latitudes, regardless of local climatical conditions. However, in order to preserve the functionality and integrity of wooden constructions, it has always been necessary to protect the wood gainst adverse agents by various means. The protection methods were being enhanced and specialized during the whole history, and they became substantially more effective with the advent of modern chemistry. Also the variety of agents aimed against various pests has broadened.
Wood is a natural material of organical nature, and it is therefore easily attackable by biotical pests, i.e. by woodworm, longhorn beetle, wood-decay funghi, and other molds and insects. These organisms represent an important part of the natural ecosystem chain, but it is advisable to avoid their presence in roof and attic spaces, since they severely damage the truss and shorten its lifetime.
Roof-bearing truss is one of the most important parts of buildings - it helps to keep the attic and the upmost floor dry and safe from water leakage. It directly influences the condition of the entire roof, which is important for habitable conditions in the whole building. Nowadays, many buildngs' trusses are endangered by wood-destroying molds, funghi and insects, because they haven't been appropriately maintained in the past. Trusses suffering from water leakage are vulnerable in particular, because increased humidity makes the adverse organisms flourish. However, even a dry and well-aired truss is susceptible to an insect attack, since the critical threshold values of wood humidity (>12%) and temperature (>10 degrees Celsius) for this kind of attack are almost always exceeded. Another kind of trusses in danger are those assembled from humid wooden beams, when repairing a roof or building an attic flat. If the wood is left without protection, its resistance is very low, and even more importantly, in case of attic flats, the toxic organical products of molds and funghi can negatively affect the health of the residents.
For all these reasons, it is advisable to regularly inspect the condition of the trusses and to apply a protective treatment from time to time. The treatments substantially prolong the trusses lifetime and clean-up the attic space from possible toxic substances. Globally, longer truss lifetime also signifies a lower wood consumption and exploitation.