Wood
Wood is a natural product. Timber or structural wood is made from trees. There are as many types of wood as there are tree species. Wood is one of the earliest materials which man used for construction purposes. Application categories are based on group affiliation (coniferous wood, deciduous wood) or on properties (light, soft timber, medium-heavy timber, and heavy, hard timber.)
Wood is a grown material with a structure and texture which has to be taken into account during processing and the production of pre-fab wood components (grain direction, sapwood/heartwood etc.). Waste products from wood processing can be adequately recycled (particle board, cellulose), however they can also present a health and environmental hazard (dust and sap from various hardwood and tropical trees). Certain tropical timbers are gained by uncontrolled cutting and ruthless exploitation of the forests which can turn whole regions into deserts and change the local climate. Increasingly so-called substitute timbers are being introduced with similar properties as tropical timbers which, however, are easier to cultivate.