Steel, aluminum, copper, and zinc are the
primary metals used in roofing. Offering great durability and low maintenance,
metal roofs can withstand high winds, blowing
embers, and heavy loads better than most
other types of roofing.
A steel roof (also known as a tin roof) is
sold in panels that interlock; these panels
can be textured to simulate shingles or may
be a simple ribbed pattern. As you would
expect, heavier panels provide greater rigidity
and thus resistance to buckling under snow
and wind loads.
A natural enemy of metal roofs is rust. To
prevent rusting, the roof is either painted
or it is galvanizing with zinc. Painting
blocks the moisture from reaching the metal
while zinc actively fights rust by "healing
over" small scratches. Premium metal
roofs use a combination of galvanizing and
paint to take advantage of both approaches
and provide long lasting protection. Because
the zinc layer thins with time, the thicker
the zinc coat, the longer the protection.
Aluminum is the low cost, low weight alternative
to a steel roof. Aluminum is corrosion resistant
and can be painted to meet the color requirements
of your home design.
Unless coated, cooper roofs begin shiny like
a new penny but oxidize into the green color
often seen on buildings built before the
early 1900's. Copper roofs, strong and resistant
to corrosion, last for hundreds of years.
However, both the material cost and the installation
is very expensive.
Zinc roofs are similar to copper
most ways except that they oxidize