There have been many ice ages during the last 2.6 million years but when people talk about the Ice Age, they are often referring to the most recent glacial period, which peaked about 21,000 years ago and ended about 11,500 years ago.
It costs roughly â¦ $11-$13 for the materials and contractors average about $5-$8 per square foot for labor, not including steps. For example, my company charges approximately $18 per square foot to build a deck.
1 Hiring someone to do the work for you makes your total cost in the range of $3,500.  You can buy the materials for a 12-foot-square redwood deck off the second floor, with a flight of steps leading to the ground, for about $6,000 and build it yourself.