In an effort to find new preservatives which are less hazardous, the efficacy of heartwood water extracts of Tectona grandis (teak) and Piptadeniastrum africanum (dahoma) (0.60 g/ml) were pressure and non-pressure impregnated into ten Ghanaian selected LUS and exposed in the field to the ground for 8 months. Visual durability ratings, hardness and mass losses were measured in assessing their field performance. Though less used timber species (LUS) retained dahoma extract more altogether, teak extract improved the durability of both pressure and non-pressure impregnated LUS more than that of...