Scan the text and describe major uses of wood in the construction industry.

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WOOD

TEXT 1.

Wood has many characteristics that make it an important construction material. It can be easily shaped with tools and fastened with nails, screws, staples, and adhesives. It is light but strong. Wood provides insulation against electricity, heat, cold, and sound. It can hold paint and other finishes, and it does not rust like metal construction materials. Wood is a renewable resource.

    Fig. 16  Some of the chief wood structural materials are round timbers, lumber, plywood, veneer products, and particle board. Round timbers include pilings, poles, and posts. Pilings are driven into the ground as foundations for buildings. Poles link overhead telephone wires and power lines. Posts are used chiefly to build fences. Lumber includes boards and larger pieces of wood that have been sawed from logs. The construction industry uses about 50 per cent of the lumber manufactured.

   We can classify lumber as softwood or hardwood. Softwood lumber comes from needle leaf trees that are also called evergreens or conifers. It is used primarily for structural work because of its straightness and length. Softwoods include pine, larch, fir, cedar. Hardwood lumber comes from trees that lose their leaves every autumn. They are widely used for flooring, furniture and paneling. Popular hardwoods include birch, maple, oak, walnut, and mahogany.

   Plywood consists of a number of thin sheets of wood called veneers that are glued together.

   Veneer products include beams that support ceilings and floors.

   Particle board is made from wood shavings, flakes, wafers, splinters, or sawdust left over in sawmills. This wood is mixed with an adhesive and pressed at a high temperature and pressure to form large panels. Particle board shrinks and swells very little in length and width.

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