Metal roofs, as evidenced by their 50-year lifespan, outlive asphalt shingles by more than three times their lifetime. While asphalt shingles are easier to install than metal roofing, they require regular maintenance and will need to be replaced in 15 to 30 years, which means an added cost to homeowners.
The term Modern era, Modern period, or Modern Times is used by historians to loosely describe the period of time immediately following what is known as the early modern period. It is to be distinguished from the term of Modernity. 1. The early modern period lasted from the end of the 15th century to the middle of the 18th century, circa 1450 (moveable type printing press etc) and 1492 (start of European Colonialism) to 1750 (the Enlightenment) and the beginning of the Industrial Revolution. 2.
The 21st century is the current century of the Anno Domini era or the Common Era, in accordance with the Gregorian calendar.It began on January 1, 2001, and will end on December 31, 2100. It is the first century of the 3rd millennium.It is distinct from the century known as the 2000s, which began on January 1, 2000 and will end December 31, 2099.n contemporary history, the 21st century began with the United States as the sole superpower in the absence of the Soviet Union, while China began its rise to becoming a superpower and the BRIC countries aim to create more balance in the global political and economic spectrum.