Metal Through The Ages of Architecture

Through the Bronze and Iron Ages of some 5,000 years ago, these metals were developing
as materials for tools and weapons. The civilisations which thrived at this
time made the most of their discoveries in metal work to create strong
hand-held tools for digging, hunting and fighting. Throughout history, the
materials used for building developed from straw and manure to wood, clay
bricks and eventually, as industry revolutionised, metal. The following are
some of the main metals used, explaining why some have been more successful
than others.
A pure metal which was once popular to work with, due to its low melting point,
is lead. It was used in water pipes and for roofing, but the former application
was soon banned when it was realised what a health hazard lead is, while the
lead used for roofing was found to deteriorate in regions of large temperature
fluctuations. One commonly known disadvantage of lead is its sheer weight,
making it tricky to use over large areas. Tin was a popular substitute for
roofing and when alloyed with copper (10% to 90%) to form bronze it became
extremely strong and actually lasts considerably longer than modern asphalt
roofing, though is still more expensive. Zinc is another alloy forming metal,
creating brass when mixed with copper, and is non-toxic as well as resistant to
pollution. When metals are coated with zinc they become galvanized and are then
protected from rust. Tin and zinc are among the lightest of metals.

The use of copper, a durable yet bendable metal, has grown in popularity over the
ages. Over 2000 years ago, it was being used to cover temple doors, while
nowadays it is a popular wall cladding choice for architects. Sheets of copper
are used in roofing due to its ability to withstand corrosion and its weight
being far less than slate and tiles. However, copper requires copper nails,
copper screws and copper bolts in order to prevent deterioration caused by
mixed metal galvanizing reactions. The Statue of Liberty is one famous use of
copper, which has weathered to its famous green hue because of the purity of
the metal.

The biggest development in architectural metal came with the implementation of
iron: cast iron, wrought iron, sheet iron and steel. Wrought iron was mainly
decorative, widely used in the 18th century to create unique
balconies, fences and gates. In the 19th century, cast iron was
taking off as a stronger yet more brittle structural metal. Used in columns,
building fronts and domes, the strength of cast iron supported other materials.
It has been used in a decorative way on staircases, grilles and verandas, but
nowadays is mainly using to create new plumbing fixtures or to refurbish
antique buildings. Sheet iron does not feature widely on exterior designs since
it is subject to rapid erosion. At the end of the 19th century,
steel (an alloy usually made of iron and carbon) was discovered as a strong,
resilient metal under compression and tension, where other metals had weakened.
Bridges, rail roads and skyscrapers were soon being constructed from steel,
which only lost strength under high temperatures so an insulating coating was
always applied. However, its strength is not guaranteed and since the 9/11
failure of the twin towers under the heat from the explosions, construction
regulations have been enforced across the USA to protect commercial buildings.
In the 1920’s, the lightweight but strong aluminium emerged. However, due to
its high cost, aluminium was originally just ornamental, until the Empire State
Building raised its profile and the construction industry took up its use.

Metal in architecture ranges from framework building and structure strengthening
techniques to decorative wire mesh cladding and balcony finishes. It has come a
long way since the tin roof era and the wide range of options is helping to make
architectural design a truly diverse art form.  

Emily is a young enthusiastic writer with particular interests in environment, science, food, technology, architecture and travel. She holds a 2:1 BSc Physical Geography (International) from the University of
Leeds and currently works as an outdoor equipment specialist and freelance article writer for CadischMDA, while searching for opportunities in energy and sustainability.