Wood is a porous material due to its cellular structure which allows for many internal voids (Eckelman). Plant cells inside the wood are designed to absorb water because it is necessary for the tree to function (“Wood and Water,” 2006). When wood first absorbs water, it is transported and held inside the cell walls. However, because these walls cannot hold a large amount of water, additional water fills the tube cell cavities located in the wood fibers. Wood is also classified as a hygroscopic material. This allows the wood to naturally absorb and dissipate water into its adjoining environment. The water density and diffusivity of wood affect the rate of water absorption in wood (Noorolahi, Khazaei, & Jafari, 2008). The hygroscopicity of wood helps control humidity in homes. For example, if the air inside a house is very humid, the wood will naturally absorb some of this humidity so that the environment reaches a more balanced and stabilized state ("About humidity and humidity"). drink "). Woods are classified as either softwood or hardwood. Softwoods generally come from conifers and hardwoods from broad-leaved trees, which are often angiosperms grown from dicot seeds. Hardwoods, unlike softwoods, have the presence of pores in the growth rings. Four common hardwoods used in construction include poplar, aspen, red oak, and red maple. Poplar has a fine grain structure and a density (ratio of density to water) of 25%. Aspen, another hardwood in the same genus as poplar, also has a specific gravity of 25%. Red oak is a very porous wood and has a specific density of 75%. Finally, red maple has a density of about 50% (Walker, ...... middle of article ......., nd Web. December 21, 2013.2. Dasch, E. Julius. Water : Science and Issues (Vol. 4). Sahebeh Jafari. “Modeling the cyclic absorption and desorption characteristics of three varieties of wood”. Web December 20, 2013. “Water absorption in coated wood – Influence of different types of wood and coatings.” , December 27, 2013.7. Walker, The Encyclopedia of Wood London: Quarto Publishing, 2005. “Wood and Water.” University of Illinois Np, July 18, 2006. Web December 20.. 2013.