Signs of the Times - November 2012 - (Page 66)

Extreme Weather and the Last Sign Standing Wind and heat are the leading culprits. By Louis M. Brill photo by YESCO It was a clutches ofstormy night, dark and with the a summer tornado sucking up everything in its path – buildings, cars, trees and whatever towering signs it could grab. In such a storm, Mother Nature has no preference, knocking down whatever she desires. Signs must withstand many environmental hazards, so I discussed with several sign fabricators how they engineer and build signs to withstand these extreme weather factors. Because signs are metal structures, they’re subjected to such entropic conditions as repetitive stress from sudden, expansive wind conditions; welding fatigue; corrosion and other natural, elemental forces that can degrade the sign’s overall structural integrity. Following are some best practices in designing and fabricating weatherproof signs. YESCO, the R. Scott Lewis & Assoc. engineering firm and Poblocki discuss their best techniques for signage installations throughout the U.S. With extreme heat, the biggest concern is its impact on a sign's electronic components. YESCO’s sign structures are designed to never approach or exceed specific temperature ranges. In most cases, forced-air convection creates a positive pressure on the inside of the sign structure, which allows the air to circulate in and out of the sign cabinet and maintain a proper temperature for the sign components. YESCO YESCO (Young Electric Sign Co., founded: 1920) designs, assembles, sells, leases, services and installs signs throughout the U.S. YESCO manager Jack Lester explained how company engineering efforts focus on various elemental weather forces. “We design our signs in accordance with the governing rules of the International Building Code [IBC], which references the ASCE-7 [American Society of Civil Engineers] and provides the minimum design loads for buildings and other structures,” Lester said. “Local jurisdictions may have additional requirements. These requirements govern our design and manufacture of sign structures and sign cabinets. A major consideration is the sign’s location relative to its surrounding structures and terrain. Mapping programs available today [such as Google Maps] make this process much easier. “Weather conditions’ effects on sign fabrication can be referenced by Hurricane Katrina. Numerous signs failed and, as a result, existing wind codes were evaluated, including researching various codes used in other countries. “Most U.S. codes subsequently changed to accommodate wind loads approximately 40% greater. Consequently, the cost of most structural elements, including poles, cabinets and footings, has increased. These ultimately get passed on to the consumer. “To evaluate these codes’ appropriateness, the Intl. Sign Assn. [ISA], in partnership with the Outdoor Adv. Assn. of America [OAAA], contracted with Texas Tech Univ. to provide full wind-load testing 66 SIGNS OF THE TIMES / NOVEMBER 2012 /

Table of Contents for the Digital Edition of Signs of the Times - November 2012

Signs of the Times - November 2012
ST Update
Technology Update
Vinyl Apps
Strictly Commercial
Lighting Techniques
The Moving Message
Technology Review
Technology Review
Design Matters
New Products
London 2012
The Rules of Attraction
Extreme Weather
An Icon Looks at 80
The Value of Signs
Enter ST ’s 2013 Intl. Sign Contest
Industry News
Industry News
Editorially Speaking

Signs of the Times - November 2012