Preventive action of organosilicon treatments against disfigurement of wood under laboratory and outdoor conditions

• Published in: International biodeterioration & biodegradation 2009-12, Vol.63 (8), p.1093-1101
• Main Authors: De Vetter, Liesbeth, Van den Bulcke, Jan, De Windt, Imke, Stevens, Marc, Van Acker, Joris
• Format: Article
• Language: English
• Subjects: Artificial weathering; Biocide; Fungal disfigurement; Fungus; General appearance; Natural weathering; Organosilicon; Pinus sylvestris; Wood treatments
• ISSN: 0964-8305; 1879-0208
• DOI: 10.1016/j.ibiod.2009.05.010

Organosilicons and biocides with known effectiveness against fungal disfigurement were used for dipping or impregnating Scots pine sapwood specimens. All specimens were artificially or naturally weathered and the colour of all specimens was determined with a spectrophotometer at fixed times. After artificial weathering the specimens were used in blue stain tests according to EN 152 or according to the EN 152 reverse method. The naturally exposed specimens were inspected for fungal disfigurement on their back side. Although the results learn that the coating approach is far better than the wood preservatives approach for evaluating blue stain attack of organosilicon-treated wood, organosilicons fail to protect wood under laboratory conditions. Outdoor exposure, however, revealed that organosilicon impregnated specimens were better protected against fungal disfigurement. The addition of a biocide improves the performance. Artificially aged specimens did not show significant colour differences compared to untreated Scots pine sapwood, while naturally aged specimens did, depending on the treatment conditions and presence of biocides. Organosilicons are able to reduce leaching of (degraded) wood constituents, leading to fewer colour changes compared to untreated scots pine and to decreased availability of nutrients for superficial fungal growth.