Several works have analyzed the alteration in the mechanical strength of wood after the application of protective substances. However, it remains unclear whether the significant differences obtained are caused by the protective substances, the pressure and vacuum conditions used in the treatment, or the simultaneous effect of both. In this study, 123 wood samples from Pinus sylvestris were tested for bending, and 85 samples were tested for compression strength parallel to the grain. These samples were randomly distributed in three groups (treated with water pressure, water vacuum, and control samples simply submerged in water). The results indicated that there was no difference in mechanical properties between the treated and untreated samples. In contrast, significant differences were detected in equilibrium moisture after a prolonged drying process.