Enhanced service life of coated wooden facades

Coated wooden claddings are widely used in Norway. But competition from other materials that has less input of labour at the construction site and less demands for maintenance is increasing. Discolouring fungi on the surface of coated wood in outdoor appl ications is an increasing concern. The total cost and effort of ownership for wooden claddings, due to repeated maintenance, can be an important factor considered when choosing a façade material. This makes further development of wooden claddings with hig h quality and long service life essential for maintaining a good market situation for wood as a façade material. New environmentally benign metal free wood protecting systems are needed. The main objective will be to develop new methods for early predic tion of durability and longer aesthetic service life of outdoor coated wooden claddings related to consumer needs and new building and environmental regulations. Two methods, qPCR and FTIR spectroscopy, will be established as objective tools for quantit ative and qualitative identification and evaluation of early colonization by discolouring fungi on painted surfaces. Further, these methods will be compared with other known standardized and non- standardized methods for quantitative evaluation of discolo uring fungi. In order to simulate natural climate exposure and material degradation, methods and procedures for artificial weathering of wood materials will be established. To find effects of variations in wood quality on the performance of coatings all w ood materials used in the project will be characterize. Wood material, wood surface structure and treatment will be studied to find the optimal combinations that serve long maintenance intervals of painted claddings. All WP's within the project will cont ribute when a procedure for aesthetic service life prediction of exterior wooden claddings due to climate exposure will be established.