{"id":2869,"date":"2015-07-20T08:00:58","date_gmt":"2015-07-20T12:00:58","guid":{"rendered":"https:\/\/roofingmagazine.com\/?p=2869"},"modified":"2016-06-09T09:56:24","modified_gmt":"2016-06-09T13:56:24","slug":"copper-clad-stainless-steel-replaces-tornado-damaged-roof-st-louis-airport","status":"publish","type":"post","link":"https:\/\/roofingmagazine.com\/copper-clad-stainless-steel-replaces-tornado-damaged-roof-st-louis-airport\/","title":{"rendered":"Copper-clad Stainless Steel Replaces a Tornado-damaged Roof at the St. Louis Airport"},"content":{"rendered":"

Hundreds of people milled about the terminals at Lambert-St. Louis International Airport on the evening of April 22, 2011. Three airplanes with passengers on board sat on the tarmac. It was business as usual at one of the largest municipal airports in the country. But meteorological conditions were anything but usual. A powerful supercell over St. Louis spawned an EF4 tornado (view the Enhanced Fujita Scale, which rates the strength of tornados by the damage caused, on page 2) packing 150-mph winds. The twister barreled directly into the airport 11 miles northwest of downtown, blowing out half the floor-to-ceiling windows in the main terminal and inflicting approximately $30 million in damages. In addition, the tornado seriously damaged part of the copper roof over Terminal 1.<\/p>\n

\"CopperPlus<\/a>

CopperPlus was installed in stages over the domes at Lambert-St. Louis International Airport. Like solid copper, copper-clad stainless steel acquires a patina over time.<\/p><\/div>The 55-year-old roof was iconic and beautiful. Its four copper domes had been the crowning glory of Lambert-St. Louis International Airport, welcoming up to 13 million international passengers each year. But the roof had been showing its age for some time, leaking often and requiring frequent maintenance. Following the tornado strike, airport officials made the difficult decision to permanently retire the roof. \u201cThe tornado damaged less than 10 percent of the total roof, but that section needed to be totally replaced,\u201d explains Jerry Beckmann, deputy airport director of Planning & Development. \u201cThat damage, plus the fact that the roof was almost 60-years old, influenced our decision.\u201d<\/p>\n

Airport officials were challenged to install more than 100,000 square feet of material over four domed vaults as quickly as possible with minimal disruption to the public. Beckmann, who is an engineer, wanted a roof that was watertight and capable of withstanding high winds while airport administrators wanted to maintain the roof\u2019s mid-century architectural integrity. All parties wanted the project completed as economically as possible with results that were aesthetically pleasing, historically appropriate and, most important, built for harsh weather events.<\/p>\n

COPPER AND STEEL<\/h4>\n

They found the solution in copper-clad stainless steel, a material that has been used in roofing applications for roughly 50 years. The selected ASTM B506-09 architectural metal features two outer layers of 100 percent copper strip roll bonded at very high pressures to a core of Type 430 stainless steel, the same metallurgical bonding process used to make U.S. quarters and dimes. The material delivered the natural beauty and patination properties of solid copper with the strength and durability of stainless steel\u2014exactly the attributes desired by officials at Lambert-St. Louis International Airport.<\/p>\n

\u201cCopper-clad stainless steel is a great-looking material that can be fabricated for any roofing style. You can\u2019t tell the difference between it and straight-up copper,\u201d says Shane Williams, vice president of Civil Construction for Kozeny-Wagner Inc.<\/a>, the Arnold, Mo.-based general contractor awarded the public bid by the city of St. Louis. \u201cIt\u2019s stronger, has a better shelf life and costs less than pure copper. This allowed us to bid competitively for the job and even return a credit to the city of St. Louis.\u201d

\"Workers<\/a>

Workers install CopperPlus batten-seam panels over a dome at Lambert-St. Louis International Airport. Step-by-step, the installation of CopperPlus is virtually identical to that of copper.<\/p><\/div><\/p>\n

The owners of Missouri Builders Service Inc.<\/a>, the Jefferson, Mo.-based roofing subcontractor, were attracted to the material\u2019s lighter weight and easy solderability. \u201cWe were going to have to maneuver a lot of material on the job site and perform a very large amount of soldering to cover four domes,\u201d notes John Kinkade, Missouri Builders Service\u2019s vice president. \u201cWe liked that copper-clad stainless steel had a lower thermal conductivity for easier soldering. That was important to us, given the scope of the project.\u201d<\/p>\n

The $6.7 million project to replace the airport roof was announced at a press conference in March 2014 by St. Louis Mayor Francis Slay, St. Louis County Executive Charlie Dooley and Lambert-St. Louis International Airport Director Rhonda Hamm-Niebruegge. \u201cThe new skin will shine of raw copper like it did in the mid \u201950s when the terminal was built,\u201d Slay stated in a press release issued by the airport. \u201cThe roof will slowly transform in color again in time as this airport serves new generations in this region.\u201d<\/p>\n

WEATHERING NATURE\u2019S WORST<\/h4>\n

Copper-clad stainless steel has become more popular in tornado and hurricane-prone regions of the U.S. in recent years, thanks to the strengthening of building codes for wind-lift and hail-resistance standards. Copper-clad stainless steel conforms to Miami-Dade BCCO requirements and exceeds UL2218 Class 4 hail-test requirements; wind-uplift tests have shown its strength to be equivalent to steel at the same gauge. It offers a strength advantage compared to solid copper, providing higher tensile strength and yield strength at a thinner gauge than monolithic copper.<\/p>\n

Numerous churches, college buildings, museums, private residences and other buildings nationwide now feature copper-clad stainless steel in their custom roofs, dormers, cupolas, flashings and downspouts. Notable installations include the following:<\/p>\n