Long-term serviceability is an important aspect in the implication of wood as a construction material. In this study, a comprehensive experimental program aims to address all the required parameters in long-term constitutive models of wood available in the literature which was taken from inconsistent sources earlier. The experimental program considers the effect of viscoelastic and mechano-sorptive creep, shrinkage and swelling, thermal and moisture inelastic deformation, and deformation due to Young’s modulus changes. The tests include tensile loading of wood specimens invariable outdoor climatic conditions in different applied stress levels. Sustained tensile loads were applied in parallel to the grain direction to specimens of Splash Pine (Pinus elliottii), Pacific Teak (Tectona grandis), and Laminated Lumber Veneer (LVL) of Radiata Pine (Pinus radiata). Tests were conducted at three different stress levels simultaneously and environmental parameters viz. temperature and relative humidity were monitored continuously throughout the loading period. Complementary data for diffusion coefficient, shrinkage, and swelling were measured in three orthogonal directions. In addition, sorption-desorption isotherm of the sample in the range of 0-100% relative humidity is presented.