The Use and Environmental Impact of Metal in Construction

The metal, of industrial and utilitarian aspect, is frequently used as material in the modern construction, as either structural element or as the finish of interior linings. The choice of metal depends essentially on their suitability, local availability and the amount of money, contractors are willing to invest.

Types of Metal

Different types of metals are used in construction such as aluminum, copper, steel, and titanium. Aluminum is lightweight, but it’s strong and has high resistance to corrosion. Copper is another type of metals used in construction. The combination of copper’s physical properties, conductivity, corrosion resistance, and strength, make it suitable for building. Steel is the most commonly used type of metal in construction because sustainable structures can be built with it at a low price. Steel is often used to build educational buildings, high-rise buildings, hospital buildings, low-rise buildings, office buildings, and stadiums. 

In homes and commercial buildings, expanded wire mesh is the type of steel metal widely used in reinforcing drywall and plaster ceilings and walls. Apart from construction, expanded wire mesh is also used in fencing and grating.

The Environmental Impact

Metal with its cold aesthetics is a durable material and invulnerable to insects. However, from the environmental point of view, the use of the metal under construction is very problematic. It is the material of construction with greater energetic expenditure, approximately 300 times more than the wood.

On the other hand, with the exception of zinc and tin that are becoming scarce, metals are very abundant in nature, which does not prevent their extraction may involve the destruction of natural habitats, and that their processing is significantly contaminating.

The metal is a material with a high thermal conductivity, that is to say, very conductive of the heat, which can imply, in certain situations, problems of thermal bridges that can compromise the energetic efficiency of the building and favor condensations and appearances of mold. Therefore, the use of the metal under construction has to be the product of a detailed technical study, especially when it comes to elements that are going to be subjected to inclement weather.

Faced with these disadvantages, it is important to note that the use of the metal under construction can carry great advantages, although it is a relatively expensive material, its recycling is much more profitable than that of other materials. For example, one-third of the existing aluminum is recycled, half of the iron needed to make steel is used, and the steel industry, in general, has a recycling rate of 68%.

There are structural beams and nails in the construction that have a recycled steel content that can reach up to 90%, even some architects use beams or reused structural elements of previous constructions.

In the case of using metal in recycled construction, the energy impact is reduced considerably. For example, the recycling of aluminum consumes only 5% of the energy that would be used to extract it and obtain the virgin aluminum.

There are critics of the use of metal in construction for the environmental reasons mentioned above, however, its supporters allege aspects such as durability, stability, the speed of execution or failure to be attacked by pests, as main advantages of the use of metal in the construction sector.

A good way to recycle the metal is to use used elements such as nails, veneers, structural beams, etc., which can be used as interior cladding elements.

Nowadays, there are studies of architects who base part of their designs on the strategy of using metallic elements for the construction of their new buildings: industrial remains, oil deposits, concrete mixers and shipping containers, and so on.