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Weathering of wood is a complex natural phenomenon that is influenced by factors both in macro and micro-scale. The degradation by weathering constitutes of complex physical-chemical changes influenced by environmental factors such as moisture, sunlight, temperature, chemical compounds, wind, and biological organisms and their related agents. The aim of our study was the evaluation of MIR and NIR spectroscopic technique for characterisation of wood treated by commercial coatings contained different biocidal treatments after weathering in subarctic conditions. Tangential and radial surfaces of the Scots pine and Norway spruce were treated with coatings containing various biocides. Treatment was in the form of fairly transparent wood oil (T), while the two others were coatings that had more of a non-transparent character (H and P). Treatedspecimens and control were placed in various directions on racks outdoor for natural weathering. The measurement of the NIR spectra of specimens that were not exposed, after weathering and dried after weathering, was done by the point-based microNIR portable sensor. Multivariate statistical analysis (MSA) showed that data from types of exposure contributed to less compared to surface treatments in the 3D principal component analysis model (PCA). Grouping pattern around treatments H and P could be obtained as the two individual groups more or less fully separated. From the treatment T and non-treated specimens, no individual grouping behaviour could be observed, however, more intense exposed seemed to be clustered in a different way than mildly exposed ones. A more extensive weather exposure gave also a more degraded surface for T-treated specimens. The NIR portable spectrometer may be used for assessment of the extent of weathering, but the treatment P followed by treatment H had minimal changes. Coefficients Plot in the PLSDA model for different types of exposure for those treatments showed the influence of the NIRwavelengths in classes related to exposure type. The changes caused by weathering phenomenon was evaluated by using multivariate methods in which resulting multivariate model parameters for prediction of the changes were determined. Analysis of the chemical structure of coatings after weathering analysed by mid-infrared spectroscopy gave support to the lower stability of T-treatmentduring weathering. ISBN för värdpublikation: 978-1-7340485-0-6

The increased concern regarding mould on wood-based building materials has raised a demand for sustainable biocidal treatments to protect early contamination during the construction stage of timber buildings. By providing surface protection for all type of wood-based construction elements already at the construction site will reduce the mould-associated risk for not only the construction elements but also for the indoor climate and dwellers at the use-stage of the building. The purpose was to test the protective effect of commercial water-based treatments containing different biocides on single mould fungi growth in pure culture. Small specimens of Scots pine sapwood and heartwood, and Norway spruce were treated with four treatments, and a fungal test performed in 90 mm Petri plates. Two samples (treated and untreated control) placed on the plate with a distance between each other, and between, a fungal inoculum placed. Five pure cultures of fungi species used in the study: Aureobasidium sp., Trichoderma sp., Aspergillus sp., Cladosporium sp., Penicillium sp. The specimens exposed at the temperature of 24°C and relative humidity of 90%. The treatments contained biocides, i.e.: treatment 1: tetramethylol acetylenediurea and iodopropynyl butyl carbamate (IPBC), treatment 2: mixture of several biocides (IPBC, benzisothiazolinone (BIT), methylisothiazolinone (MIT) and 5-chloro-2-methyl-1,2-thiazol-3-one (CMIT)/MIT mixture), treatment 3: IPBC; and treatment 4: mixture of propiconazole and IPBC. The fungal growth observed in the untreated samples after four days of incubation, the specimens with treatment 4 attacked after eight days, when treatment 1 and 3 had free from fungal mycelia inhibition zone after 22 days of incubation. The moisture content after the test was similar for treated samples in plates with Aureobasidium sp., Aspergillus sp., Cladosporium sp., Penicillium sp., but was significantly higher for Trichoderma sp. The type of wood did not influence fungal growth in comparison to the type of treatment.