by Nick Gromicko, CMI®
Steel is one of the world's most important engineering and construction materials, and increasingly a material of choice in commercial and residential applications.
Although no one is certain when it was first used, a British inventor named Henry Bessemer is credited with creating the first technique by which steel could be mass-produced. Today, the metal is produced by adding a small amount of carbon to iron ore, and removing impurities, such as sulfur and phosphorous. Small amounts of alloying metals, such as nickel, manganese, chromium and vanadium may also be added.
Facts About Steel
- There are currently more than 3,500 different grades of steel, most of which have been developed within the last few decades. The Eiffel Tower, if it were built using modern varieties of steel, would require only one-third as much steel as was used in 1889 when it was constructed.
- The recent economic boom in China and India has caused a massive increase in the demand for steel.
- China is the world’s top steel producer, followed by Japan, Russia, and the United States, respectively.
The physical properties of steel offer significant advantages over concrete, wood, and other building materials. Here are some of these advantages:
- Steel is highly recyclable. In the United States, more steel is recycled than plastic, glass and aluminum combined, making it the most recycled material nationally. The reason for this is threefold: first, by virtue of its magnetic properties, steel can be easily separated from the waste stream. Second, recycling saves the steel industry an enormous amount of energy -- enough to power 18 million homes for one year, according to the Steel Recycling Institute. Third, recycled steel loses none of its properties, making the recycling process simple and efficient.
- Steel use saves trees. A typical 2,000-square-foot house, which requires 26,700 board feet to build, would require the use of 102 trees, according to the the Idaho Forest Products Commission.
- More windows can be integrated in structures of steel construction, due to elevated mechanical properties of the metal. Windows reduce energy consumption and increase the comfort of building occupants.
- Steel has the highest strength-to-weight ratio of any comparable construction material, making it among the most durable.
- Steel conforms to any aesthetic. The availability of finishes, facades and other wall claddings allows builders to craft steel structures in any fashion.
- There is an unlimited production capacity. Steel’s main ingredient – iron – is one of the most common metals in the earth’s crust. The United States’ structural steel industry has the capacity to produce 6 million tons of structural steel per year, which is comfortably more than what will be needed in the foreseeable future.
- Steel is economical due to its enhanced quality and reduced costs owing to off-site fabrication and rapid construction.
- Steel is non-combustible, which allows for lower insurance costs.
Steel in Residential Construction
Steel has long been a staple in commercial construction, but the material has seen recent use in residences, as well. Increasing lumber prices and a need to conserve timber products, as well as design elements such as resistance to termites, are fueling the transition to steel in the residential construction market. In addition, steel offers excellent earthquake, fire- and wind-resistance. Steel ceiling joists can span greater distances than wooden ones, allowing for a broader range of design possibilities for builders and architects. A disadvantage, however, is that steel readily conducts heat and cold, which may degrade a home’s energy efficiency. Contractors can mitigate this potential by wrapping steel framing in insulation board, as well as by placing insulation batts between the studs. Also, noise due to thermal expansion and contraction, as well as that produced by heavy rain, may cause irritation for occupants. Steel is often used in houses in the following applications:
- rebar within concrete foundations;
- floor joists, floor bearers and columns used to raise houses off the ground;
- wall framing; and
- battens, trusses and roof sheeting.
In summary, steel is an excellent building material for residences as well as commercial buildings.