Beam construction is both the way structural beams are put together and the methods for using those beams to build structures. While there are several different types of beams, nearly all structural beams are made of wood, steel or a combination of the two. The two most common shapes for beams are long rectangular boxes, common in wood and composites, and ones shaped like the letter ‘I,’ common with steel beam construction.
Since the early days of construction, wood has been a common material used in beam construction. Wood is the most common material used in the construction of residential buildings. There are several types of wooden beams made, but they fall into a couple of categories.
Standard wooden support beams are vertical beams used primarily in houses. These beams are thick, rectangular blocks of wood that support the basic structure of a house. They are found in corners of buildings and in the center of the house inside the walls, often near doorways. Many houses, particularly older ones, have support beams throughout the basement supporting the entire structure.
Floor joists are another common wooden support beam. These beams are horizontal and are in the floors and ceilings of houses. These help to spread the weight of the structure above it, putting less stress on any one area of the house. It is common to see these in older house basements as well; they are often much thinner than wide in contrast to the horizontal beams, which are generally evenly-sized.
Wooden beam construction is done one of four ways. Rough-cut timbers are common in older houses; these are actual trees that were cut into the shape of the beam and used as is. Modern beams are generally factory-cut and treated. Wooden beams are simply treated lumber with no additional modifications. These beams are generally the same as the old rough-cut ones, just in a newer form.
Composite or laminate beams are made of several smaller beams compressed together into a single beam. These beams are stronger and more durable than a standard wooden beam. Steel-reinforced beams generally have a steel core through the middle and/or a series of metal bands wrapped around the outside. These are common in extremely heavy or high-traffic buildings.
Steel beam construction revolves around two types of beams—the vertical round beam and the I-beam. Vertical round beams are used as an emergency beam support in a situation where a building may collapse. These beams were not present when the building was made; they are added later.
The I-beam has two flat surfaces connected by another flat surface, giving it the shape of an ‘I’ or an ‘H.’ These beams are used in large structures, as steel can hold much more than wood. Unlike wooden beams, there is very little variation in beam construction with I-beams. Whether they are in a wall, floor or foundation of a structure, they are made the same way.
By M. McGee