Poškození dřeva působením anorganických sloučenin

Wood constructions used to be treated with inorganic preservatives. Arsenic, chromium, copper, zinc, boron and fluorine compounds and sodium chloride were used to protect wood against biological attack. Ammonium salts (mainly phosphates and sulphates) and boron compounds were used as fire retardants. But higher amount of inorganic compounds in wood structure may cause defibration of the wood surface. In the Czech Republic (e.g. the roof structure of the Malostranska mostecka věž in Prague), this type of deterioration was observed on historic roof structures treated with inorganic fire retardants or inorganic preservatives. Defibration is caused by the degradation of middle lamella, secondary cell wall may be damaged as well. Repeated recrystallization of salts in the wood structure seemed to be the main cause of defibration. New studies propose that a presence of inorganic compounds participate on the degradation of wood components, acid hydrolysis or lignin oxidation is supposed to be the main reaction mechanism.