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The types of
metal that are used in architectural work include:
• Lead
• Tin
• Zinc
• Copper
• Nickel
• Iron
We will examine each of these metals more closely below.
Lead
Lead has a low melting point, which is a quality that
has promoted its use for centuries. In fact, prior to
the late 19th century discovery that lead can cause
health issues in humans if it is consumed even in trace
amounts, many pipes that delivered drinking water were
constructed of lead. Lead also has non-corrosive qualities,
which caused it to be added to paint for many years.
This too is no longer a common practice due to the prevalence
of paint in homes and the negative health effects that
lead can have on humans if consumed.
Lead has been used ubiquitously in roofing, gutters,
downspouts, flashing, and conductor heads. Lead is also
frequently used as the metal framing for stained glass
or other intricate glass window work.
Tin
Tin is frequently alloyed with copper to form bronze.
It is also frequently used to coat harder metals such
as steel or iron. Because tin is a soft metal, when
it is used alloyed with copper to form bronze, the distribution
of metals is about 90% copper and 10% tin.
When a harder metal is coated in tin, it is referred
to as “tinplate”. Tin roofs and tin ceilings
are both examples of tinplating, not use of pure tin.
Zinc
Zinc was initially used as a roofing material in Europe,
most prominently in the nations of Germany, France,
and Belgium. Later, zinc-coated materials began to arise.
Galvanized sheet iron coated in zinc gained popularity
in the mid-1800s.
Zinc has also been used in decorative elements, again
predominately in Europe. In the United States, zinc
has lost some of its popularity as a roofing or decorative
material, however it has been gaining some steam as
of late.
Copper and Copper Alloys
Copper is a durable material that can withstand corrosion
once it forms a patina, which is bluish-green in color.
Famously, the Statue of Liberty is made of copper and
is covered in this patina. Copper is a fairly expensive
material, however due to its durability, the cost is
often seen as worthwhile. Copper is used decoratively
and in projects that require shaping such as chimneys
and roof edges. When used in nails, screws, etc. copper
is alloyed to prevent deterioration.
Nickel and Nickel Alloys
Nickel is used in buildings most frequently in the form
of alloys. Common nickel allows include Monel metal,
stainless steel, and nickel silver.
Nickel Silver contains 75% copper, 5% zinc, and 20%
nickel while Monel metal is approximately 66% nickel
and 33% copper. Nickel silver varies in its coloring
depending on the specific percentage makeup, whereas
Monel Metal tends to be bronze in coloring.
Iron and Iron Alloys
Iron is very commonly used in architectural work in
the form of wrought iron, sheet iron, steel, and cast
iron. Steel is an important application of iron and
comes in the form of stainless and copper-bearing steel.
Both are used commonly in architectural metal work.
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