Thermal modification is a process capable of improving properties affecting wood performance, such as biological durability. This study aimed to assess the potential of thermal modification in enhancing the resistance of Couratari sp. wood to deterioration by Trametes versicolor, Nasutitermes corniger, and Cryptotermes brevis. Five treatments were analyzed, represented by the untreated and thermally modified wood at 180, 190, 200, and 210 °C. The wood’s chemical composition and resistance to biodeterioration in laboratory tests were evaluated. Thermal modification, especially at 210 °C, altered the chemical composition and increased the wood’s durability class against the fungus. However, the process did not affect termite attack. There was a significant positive correlation between corrected mass loss and hemicellulose and total extractive contents, as well as mass loss caused by T. versicolor and lignin and hemicellulose contents. The use of thermal modification in 190 °C is recommended for Couratari sp. wood due to its enhanced biological durability, with 210 °C being particularly effective.
