Untreated and nano-based compound treated chestnut, wild cherry, fir, and black pine wood samples were immersed in water at four different temperature levels. It was found that the nano-based compound was a very effective agent for lowering both the initial and maximum equilibrium transverse swelling of wood. However, the latter were found to have similar trends as the initial swelling properties. The surface treatment appeared not to improve the maximum water absorption. The highest average activation energy was calculated for chestnut (23.1 kJ/mole), followed by pine (20.2 kJ/mole), cherry (18.1 kJ/mole), and fir (16.2 kJ/mole). However, the nano-based treatment resulted in a small increase in activation energies of all wood species. It was found that absorption of water into wood as well as increasing temperature had a lowering effect on shore D hardness.