This study investigated the natural durability of 8 and 60 year old Eucalyptus bosistoana (coast grey box). The sample’s heartwood compounds were extracted with an optimised extraction process and then incorporated into agar. Trametes versicolor (white rot) and Gloeophyllum trabeum (brown rot) fungi were grown upon these agars and their growth rate was used to assess the fungicidal abilities of the extracts. The extraction method of cell wall compounds was optimised. An Accelerated Solvent Extraction system (ASE) was used with the following settings: • 2 cycles per sample • 70°C extraction temperature • 50% rinse • 5 minute static time Ethanol was found to extract the compounds of the highest fungicidal activity. Ethanol was found to extract similar amounts to water (~13% of dry weight for a 60 year old sample), however analysis of both water and ethanol extracts with a FTIR spectrometer, found that they were of different chemical composition. A difference in fungicidal activity of extracts was found between the 8 year old and 60 year old samples. There was a large difference in the percentage of extracts present between the samples as well as the type of compounds present, shown by FTIR.