A Half-yearly Peer Reviewed Journal of Bangladesh Forest Research Institute
Wood, is a hygroscopic substance. It has the ability to adsorb and desorb moisture. When wood is exposed to atmospheric condition its moisture content adjusts itself until it is in equilibrium with the moisture content of the surrounding atmospheric humidity. The equilibrium moisture content of wood is dependent on the atmospheric temperature and relative humidity and consequently a change in temperature and relative humidity will bring about a change in the moisture content of wood. This fluctuation of moisture content is generally accompanied by a corresponding change in the dimension of the wood. The situation becomes complicated by the fact that the dimensional change is not same for all the species. Some timbers are comparatively stable in respect of shrinkage and swelling while others are more susceptible to such changes causing trouble during wood in service, particularly in joinery work, such as, drawers, doors and windows, etc. Thus knowledge on the seasonal variation of moisture content of different species of wood and their concomitant dimensional changes is of considerable practical importance in determining their suitability for good quality furniture and cabinet manufacture. A study was, therefore, undertaken to evaluate the relative dimensional stability properties of some of the indigenous wood species of Bangladesh where temperature and relative humidity conditions of the atmosphere between the winter and monsoon months vary widely.