which wood become useless soon after exposing in the Open air ?
Wood is a porous material and will absorb moisture from the air. Moisture is attracted to the walls of the tubes that make up the wood. Wood will only decay if it is in contact with the ground or wetted by an external source of moisture, such as rain seepage, plumbing leaks, or condensation. Dry wood will never decay. Also, the drier the wood, the less likely it is to be attacked by most types of wood-inhabiting insects. Wood-inhabiting fungi are small plants that lack chlorophyll and use wood as their food source. All fungi require moisture, oxygen, warmth, and food. The keys to preventing or controlling growth of fungi in wood in buildings are to either keep the wood dry (below moisture content of 20 percent) or to use preservative-treated or naturally resistant heartwood or selected species.