Issue link: https://read.dmtmag.com/i/117828
70 ��� APRIL 2013 ��� WORLD FENCE NEWS Installation of Acoustifence quiets construction noise at Santa Monica High School continued from page 44 chain link construction fencing is commonly used at construction sites to help prevent theft and damage to machinery, equipment, and property, as well as provide security and privacy for the construction crew. Acoustic construction fences are specialized barriers often used when construction noise may negatively impact those around the construction site. The Santa Monica High School Project Acoustifence ranges in height from 14 feet���20 feet at different parts of the construction site and zigzags around the perimeter near the street and the existing school building. In addition to the construction fence, Acoustifence soundproofing material was placed over the side of the top portion of the school building to help make the second floor quieter for students during construction. ���Our heavy equipment machines emit between 90-100 decibels of noise while operating depending on the machine itself. Throughout the day, these machines are sometimes located 250300 feet away from the school building making it virtually impossible to contain all the noise,��� Nadalet said. Heavy equipment machines are needed to build large buildings and rebuild a large area like at Santa Monica Above, FenceCorp���s bid drawing shows the zig zag shape of Santa Monica High School Science and Technology Building Project acoustical construction fence. Clear identification labels were added by the writer to show location of school buildings, the existing ball field, nearby businesses, and residences. High School. According to the U.S. Environmental Protection Agency, noise from various construction machines can range from 70-95 decibels at 50 feet. One front loader can reach approximately 83 decibels; scrapers, graders and backhoes approximately 92 decibels; concrete mixers and cranes approximately 88 decibels, earth moving tractors can reach approximately 95 decibels. A single jackhammer can reach nearly 100 decibels and a pile driver reaches approximately 105 decibels. So a 10-decibel decrease in construction noise helps keep it within a more tolerable range. ���The Acoustifence noise barrier wall is located about 10 feet from the school building so our machines are not always located within close proximity to the noise barrier fence. We work hard to keep construction noise as minimal as possible while moving the project forward to meet our deadlines,��� Nadalet said. Noise intensity is measured in decibel units. The decibel scale is logarithmic; each 10-decibel increase represents a tenfold increase in noise intensity. Human perception of loudness also conforms to a logarithmic scale; a 10-decibel increase is perceived as roughly a doubling of loudness and a 10-decibel decrease is perceived as half as loud. A typical conversation occurs at 60 decibels ��� not loud enough to cause damage. If a sound reaches 85 decibels or stronger, it can cause permanent damage to a person���s hearing with prolonged exposure. The amount of time continued on page 75