 Builders break up layers of naturally fallen snow into powder and thoroughly mix bottom and top layers of snow to increase sintering, thus strengthening the eventual structure.Snow is typically piled 1.5 to 2 meters (6 to 10 feet) high in a dome 3 to 4 meters (10 to 12 feet) in diameter.It is then left for at least 2 hours to sinter, allowing both temperature and moisture in the snow to homogenize and the snow crystals to bond with each other.