Abstract:

Indirect conservation or preventive conservation aims the preservation of the cultural heritage by controlling the environmental factors related to the deterioration of building materials. Indirect conservation of an historic building or museum basically includes the research on the building and its collection, risk analysis, monitoring, periodic control, preventive conservation and preventive maintenance. Research on the effects of environmental conditions on museum objects and historic buildings gained importance especially after 1970s and the importance of preventive conservation and maintenance emphasized in the international preservation documents together with the increasing emphasis on authenticity and minimum intervention. After 1990s preservation problems of museums in historic buildings started to be discussed independently from the museums in modern buildings and research focused on the joint preservation of the historic buildings and the collections.Preventive-indirect conservation of an historic building or a museum composed of research on the building and the collection, analysis of the risks, monitoring, periodic control, preventive conservation and preventive maintenance. Visual analysis at the beginning of the research in Dolmabahçe Palace pointed out preservation problems related to environmental factors. The research on the environmental factors includes microclimate, moisture content of the building materials, soluble salts, and problems related to unsuitable light, indoor pollution and biodeterioration. The major risks that are found can be summarized as; The risk of deterioration due to rot fungi and wood borers as a result of high relative humidity in the basement and wooden elements in contact with the damp masonry. Airborne mould species discovered are known to be harmful to paper, wood and textiles. There is risk of crystallization of sodium chloride on the first floor walls and of calcium sulphate in the basement. There is also risk of deterioration due to high temperature and illumination level, visible light and ultraviolet radiation for the objects made of organic materials located near to the windows in the rooms of southern and western exposure. High temperatures measured in summer create deterioration risk for book collection, paper objects and photographs. Indirect conservation methods suggested include preventive measures, monitoring, periodical control and maintenance program proposed within the concept of the indirect-preventive conservation

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