From 970 B.C., when metal coverings were installed on the temple in
Jerusalem, to modern times, metal roofing has been used continuously. The Europeans were masters in the use of metal roofs to protect buildings,
including such famous architectural achievements as the Pantheon in Rome
(2nd century A.D.) and Notre Dame Cathedral (12th century A.D.).
The craft was imported to the Western Hemisphere about the time of the
American Revolution. Early installations in the "New World" include Monticello
in Charlottesville, Virginia and Christ Church in Philadelphia.
When steel was introduced into construction at the beginning of the 20th century,
a new affordable building material became available for roofing. Metal was rolled
into flat sheets stiffened by ridges then dipped into molten zinc to protect them
from corrosion. All of this, when fabricated by an automated process in a steel
mill, produced the cheapest and most available metal roofing material on the market,
and its use grew tremendously.
Most recently, with the technological advances in automated roll-forming, coatings,
sealants and fastening systems, metal has become the fastest growing material
used in roofing today. The metal industry projections show that roofing with metal
will triple within the next five years.
The continued demand and increase for metal roofing has involved the
products of today to get Energy Ratings for energy efficiency as well as
the highest ratings for Fire Resistance (class 'A'), class IV impact hail
resistance, 120mph-plus wind resistance, and installed shear values
against earthquakes, without the need of additional 1/2" plywood decking.