When used outdoors or in high humidity interiors, wood highly is susceptible to decay by biotic and abiotic agents. Applying coating systems that contain compounds able to control decay is a way to increase the useful life of the wood. Gleditsia triachantos is regarded as a plague in many countries due to its resistance to extreme environmental conditions and its displacement of native forests. In this work, Eucalyptus grandis and Pinus taeda wood samples were treated with waterborne acrylates, linseed oil, alkyd resins on their own and combined with extractives from Gleditsia triachantos. Heartwood and bark extractives were compared. The viscosity of the coating mixtures was measured at room temperature with a Brookfield viscometer. The resistance of the treated samples against white rot (Trametes versicolor) and brown rot fungi (Gloeophyllum separium) under controlled conditions was determined. After three months of natural weathering, the samples were visually ranked on coating erosion and wood splitting. Their appearance was analyzed and the surface area of its checks was measured. Results showed a sharp increase in resistance against fungi when treated with extractives. General appearance and coating erosions depended on the type of coating rather than on the use of the biocidal extractives.

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