Coating System Makes Roofing and Cladding Appear Aged, Weathered

Bossier City, La.-based McElroy Metal’s Cor-Ten AZP Raw is new to the company’s product line, offering the look of aged or weathered roofing and cladding.

Cor-Ten AZP Raw is a fluoropolymer coating system that uses cool pigment technology that McElroy Metal applies over Galvalume-coated steel sheet. It’s available in a variety of McElroy Metal standing-seam and through-fastened panel profiles. The look of aged or weathered roofing and wall cladding is growing in popularity and used in commercial, residential and industrial applications. Cor-Ten AZP Raw provides the appearance of rusted metal with the advantages of a highly reflective PVDF coating.

“We’re offering the appearance of weathered steel without having to wait for time and Mother Nature,” says Ken Gieseke, vice president of Marketing at McElroy Metal. “As soon as it’s installed, the weathered aesthetic is evident, attractive and durable. It’s sure to become a popular choice of architects and building owners seeking the look of weathered steel.”

In 2005, U.S. Steel introduced Cor-Ten AZP prepainted steel sheet to provide architects, building owners and homeowners with an enhanced performance product to its Cor-Ten steel. McElroy Metal offers the moderately weathered Cor-Ten AZP Raw, a carefully crafted and engineered system to provide any roofing or cladding project with the authentic look of timelessness.

Raw is produced by McElroy Metal in collaboration with Valspar and U.S. Steel.

To learn more, visit here or call (318) 747-8000.

Scissor Shears Cut Thin Coated Metals

When cutting thin coated metals, the swiping cut action of the scissor shears seals the edges of the cut material, reducing the likelihood of rust or corrosion.

When cutting thin coated metals, the swiping cut action of the scissor shears seals the edges of the cut material, reducing the likelihood of rust or corrosion.

Kett Tool Company helps plastic fabricators, siding installers and sign companies conserve materials with the swiping cut action of the KD-441 Scissor Shears. When cutting thin coated metals, the swiping cut action of the KD-441 seals the edges of the cut material, reducing the likelihood of rust or corrosion.
                                                                                                  Kett’s KD-441 use a five-amp pistol grip, 0‐2,500 RPM variable-speed electric motor that cuts through cold rolled (C.R.) mild steel (up to 24 gauge), wire mesh to 18 gauge, spiral pipe, metal studs, plastics and rubber, with a scissor action – all at speeds up to 2,500 strokes per minute. The scissor shears weigh five pounds and have an adjustable cutting speed that can be tailored for individual cutting needs. All shear heads are precision made in the U.S. featuring A-2 tool steel blades for durability.  
 
The KD-441 Scissor Shears are available through authorized dealers. For more information or to locate a dealer, visit the website or call (513)271-0333.

Shear Cuts Metal while Conserving Materials and Costs

Kett Tool Co.’s KD-400 18-Gauge Double-Cut Shears help manufacturers and contractors conserve materials and cut costs. The shears deliver precision cuts in cold rolled (C.R.) mild steel, stainless steel, aluminum, plastic and Formica without warping or bending the original material or the finished piece.

Kett Tool Co.’s KD-400 18-Gauge Double-Cut Shears help manufacturers and contractors conserve materials and cut costs.

Kett Tool Co.’s KD-400 18-Gauge Double-Cut Shears help manufacturers and contractors conserve materials and cut costs.

The Double-Cut Shears’ dual blades transfer any distortion produced in cutting to a small 7/32-inch waste strip, leaving behind material edges that are not hardened or burred to allow maximum use of sheet material. The blades’ swiping action also seals edges of coated metals.

Kett’s KD-400 shears use a 5-amp, variable speed, 2,500 RPM electric motor to produce straight or contoured cuts in C.R. mild steel (up to 18-gauge), most grades of stainless steel to 20-gauge, aluminum to 0.080 inches, and plastic or Formica up to 3/32 inches thick—all at speeds of up to 300 inches per minute. The lightweight, maneuverable shears easily follow a scribed line, capable of cutting a radius as small as 6 inches.

The KD-400 Double-Cut Shears are also available with a contour cutting blade 60-21C to cut tighter curves and the HS blade 60-21HS for cutting foam filled doors. All shear heads are precision made in the U.S. featuring A2 tool steel blades for prolonged durability.

The KD-400 Double-Cut Shears are available through authorized dealers.

Contemporary Materials Are Used to Preserve a Historically Significant 1889 House

In my capacity as a historic preservation contractor and consultant, I am often afforded the opportunity to become involved in exciting and challenging projects. Recently, my firm was awarded the contract to restore the clay tile roof turrets at Boston’s Longy School of Music’s Zabriskie House. Now part of Bard College, Longy School’s Zabriskie House is actually the historic Edwin H. Abbot House with a sympathetically designed addition built in the 1980s. The deteriorated condition of the original house’s turrets, as well as lead-coated copper gutter linings and masonry dormers, had attracted the attention of the Cambridge Historic Commission, and a commitment to the proper restoration of these systems was struck between the commission, building owner and a private donor.

The hipped roof turret on the building’s primary façade was in need of serious attention.

The hipped roof turret on the building’s primary façade was in need of serious attention.

BUILDING HISTORY

Before I can specify historically appropriate treatments, I need to don my consultant’s cap and dig into the history of a building to best understand its evolution. Developing the background story will typically answer questions and fill in the blanks when examining traditional building systems. An 1890 newspaper clipping held by the Cambridge Historic Commission re- ports that “[t]he stately home of Mr. Abbot, with its walled-in grounds, on the site of the old Arsenal, promises to be the most costly private dwelling in the city.” An examination of records held by the Massachusetts Historical Commission and from the Library of Congress’ Historic American Buildings Survey reveals that the firm of Longfellow, Alden & Harlow designed the Richardsonian Romanesque portion of the building and that Norcross Brothers Contractors and Builders was the builder of record.

Alexander Wadsworth Longfellow Jr. (of Longfellow, Alden & Harlow) was the nephew of the famous poet Henry Wadsworth Longfellow and an important figure in U.S. architectural history. After graduating from Harvard University in 1876, he studied architecture at the Massachusetts Institute of Technology and the École des Beaux-Arts in Paris, after which he worked as a senior draftsman in Henry Hobson Richardson’s office. After Richardson’s death in 1886, Longfellow partnered with Frank Ellis Alden and Alfred Branch Harlow to found the firm of Longfellow, Alden & Harlow. With offices in Boston and Pittsburgh, the firm designed many important buildings, including the Carnegie Library in Pittsburgh and the City Hall in Cambridge.

Norcross Brothers Contractors and Builders was a prominent 19th century American construction company, especially noted for its work, mostly in stone, for the architectural firms of Henry Hobson Richardson and McKim, Mead & White. Much of the value of the Norcross Brothers to architectural firms derived from Orlando Norcross’ engineering skill. Although largely self- taught, he had developed the skills needed to solve the vast engineering problems brought to him by his clients. For example, the size of the dome at the Rhode Island Capitol was expanded very late in the design process, perhaps even after construction had begun, so that it would be larger than the one just completed by Cass Gilbert for the Minnesota Capitol. Norcross was able to execute the new design.

BUILDING STYLE

The Edwin Abbot House is an interesting interpretation of the Richardsonian Romanesque style. Whereas the great majority of such buildings feature rusticated, pink Milford granite in an ashlar pattern, trimmed with East Longmeadow brownstone, Longfellow created a unique spin for Mr. Abbot. Although the building is trimmed with brownstone, the field of the walls features coursed Weymouth granite of slightly varying heights. The motif of orange, brown and golden hues of the stone is continued in the brick wall surrounding the property.

Scaffolding was erected that would make the otherwise dangerous, heavy nature of the work safe and manageable.

Scaffolding was erected that would make the otherwise dangerous, heavy nature of the work safe and manageable.

The roof is covered in a flat, square orange-red clay tile. Richardsonian Romanesque buildings are almost exclusively roofed in clay tile; Monson black slate; Granville, N.Y., red slate; or some combination thereof. It should be noted that because their need for stone was outpacing the supply, Norcross Brothers eventually acquired its own quarries in Connecticut, Georgia, Maine, Massachusetts and New York.

The roof framing system of steel and terra-cotta blocks is relatively rare but makes perfect sense when considered in context with the latest flooring technologies of the era. A network of steel beams was bolted together to form the rafters, hips and ridges of the frame. Across each is welded rows of double angle irons (or inverted T beams). Within these channels, in beds of Portland cement, the terra-cotta block was laid. The tile was then fastened directly to the blocks with steel nails. Because of the ferrous nature of the fasteners, the normal passage of moisture vapor caused the nails to rust and expand slightly, anchoring them securely in place. Whether this element of the design was intentional or simply fortunate happenstance, the result made for a long-lasting roof.

What doesn’t last forever in traditional slate and clay tile roofing systems is the sheet-metal flashing assemblies. Over the years, there must have been numerous failures, which led to the decision to remove the clay tiles from the broad fields of the roof and replace them with red asphalt shingles in the 1980s. Confronted with the dilemma of securing the shingles to the terra-cotta substrate, a decision was made to sheathe the roof with plywood. Holes were punched through the blocks and toggles used to fasten the plywood to the roof. In an area where the asphalt shingles were removed, more than 50 percent of the plywood exhibited varying degrees of rot caused by the normal passage of vapor from the interior spaces.

Fortunately, the turrets had survived the renovations from 30 years before. A conical turret in the rear and an eight-sided hip-roofed turret on the north side needed only repairs which, while extensive, did not require addressing issues with the substrate. The 16-sided turret on the primary façade of the building was in poor condition. Over the years, prior “repairs” included the use of non-matching tiles, red roofing cement, tar, caulk and even red slate. A scaffold was erected to allow safe, unfettered access to the entire turret and the process of removing the tile began. Care was taken to conserve as many tiles as possible for use in repairing the previously described turrets.

As the clay-tile roof covering was removed, the materials of the substrate were revealed and conditions were assessed.

As the clay-tile roof covering was removed, the materials of the substrate were revealed and conditions were assessed.

The substrate was examined closely and, save for thousands of tiny craters created by the original nails, found to be sound. A new system had to be devised that could be attached to the terra-cotta blocks and allow for the replacement tiles to be securely fastened, as well as resist the damaging forces of escaping moisture vapor. Cement board, comprised of 90 percent Portland cement and ground sand, was fastened to the blocks with ceramic-coated masonry screws. The entire turret was then covered with a self-adhering membrane. The replacement tiles were carefully matched and sourced from a salvage deal- er in Illinois and secured with stain- less-steel fasteners. The flat tiles, no longer manufactured new, are referred to as “Cambridge” tiles for their prevalence on the roofs of great homes and institutional buildings in and around Cambridge.

CONTEMPORARY UPDATES

Although I typically advocate for the retainage of all historic fabric when preserving and restoring traditional building systems, there are exceptions. In the case of the Abbot House roof, we encountered “modern” technologies that pointed us toward contemporary means and methods. Rusting steel nails in the terra-cotta block were brilliant for initial installation but seemed ill conceived for a second-go-round. Instead, using non-ferrous fasteners and a new substrate that is impervious to moisture infiltration will guarantee the turret’s new service life for the next 125 years or more.

ROOF MATERIALS

Self-adhering Membrane: Grace Ice & Water Shield
Masonry Anchors: Tapcon
Cement Board: James Hardie
Stainless-steel Roofing Nails: Grip Rite
Replacement Tiles: Renaissance Roofing Inc.

PHOTOS: Ward Hamilton

Lightweight Shears Easily Cut Cold Rolled Mild Steel

Kett Tool offers maneuverability for cutting corrugated metal with the left curved blade configuration of the KD-446L Profile Shears.

Kett Tool offers maneuverability for cutting corrugated metal with the left curved blade configuration of the KD-446L Profile Shears.

Kett Tool offers contractors, installers and manufacturers maneuverability for cutting corrugated metal with the left curved blade configuration of the KD-446L Profile Shears. The lightweight shears can easily cut cold rolled (C.R.) mild steel up to 18 gauge at a radius as tight as three inches.

The KD-446L features a powerful 5-amp pistol grip, variable speed, 2,500 RPM motor that easily cuts profile and flat materials up to 18 gauge C.R. mild steel, soft non-ferrous metals like aluminum, copper and brass (up to .090-inch thick); spiral duct, wire mesh and many other sheet materials—all at speeds of up to 28 feet per minute. The tool is lightweight at 5 pounds and has a 3-inch cutting radius, allowing for maximum maneuverability when cutting tight curves. The cutting blades are made from high-quality steel, heat treated and precision ground for extended operation.

Shears Cut and Contour Steel

Kett Tool’s KL-200 Double-Cut Shears deliver precision cuts and contours in C.R. mild steel (up to 18 gauge), stainless steel (to 20 gauge) and more materials without warping or bending the original material or finished piece.

Kett Tool’s KL-200 Double-Cut Shears deliver precision cuts and contours in C.R. mild steel (up to 18 gauge), stainless steel (to 20 gauge) and more materials without warping or bending the original material or finished piece.

Kett Tool’s KL-200 Double-Cut Shears deliver precision cuts and contours in C.R. mild steel (up to 18 gauge), stainless steel (to 20 gauge) and more materials without warping or bending the original material or finished piece. The dual blades transfer any distortion produced in cutting to a small 7/32-inch waste strip, leaving behind material edges that are not hardened or burred to allow maximum use of sheet material. The blades’ swiping action also seals edges of coated metals. The shears’ 4-amp straight handle and single-speed electric motor operate at speeds up to 300 inches per minute. All shear heads are precision made in the U.S. featuring A-2 tool steel blades for prolonged durability.

Traditional Wood Shakes Are Made of High-strength Steel

The Roser Stone Wood Shake pairs the aesthetic beauty of the traditional wood shake with the low maintenance and exceptional performance of high-strength steel.

The Roser Stone Wood Shake pairs the aesthetic beauty of the traditional wood shake with the low maintenance and exceptional performance of high-strength steel.

The Roser Stone Wood Shake pairs the aesthetic beauty of the traditional wood shake with the low maintenance and exceptional performance of high-strength steel. Tested against the elements, Stone Wood Shake by Roser has been tempered against hurricanes, fires, hail storms and earthquakes and has proven its durability and protection for your greatest investment—your home.

The roofing system includes:

  • Clear acrylic over-glaze protective coating
  • Roofing granule coating
  • Adhesive basecoat
  • Protective surface coating
  • Aluminum/zinc coating
  • Commercial-grade steel core
  • Protective surface coating

The Stone Coated Steel Roofing System, manufactured by Roser, offers the advantage of high-strength steel with a look a variety of traditional and innovative architectural styles. When compared to asphalt shingles and concrete roofing products, which can weigh 350 to 1,000 pounds per square, the Roser Stone Coated Roofing System, at only 150 pounds per square, effectively reduces the overhead weight on the house structure. This provides for a much safer building during an earthquake, fire or a hurricane. While the standard shingle and shake roofs naturally deteriorate over time, the Roser Roofing System will continue to maintain its beautiful appearance and requires the least amount of maintenance in the roofing industry. An eco-friendly Roser roof will increase the resale value of your home not only with its elegance, but also with its proven durability.

About Roser Roofing System:

  • Installs direct to deck or over battens.
  • Stone surface resists fading and provides for a quiet roof.
  • Fastener design features a confirmed and a locking profile.
  • Low-maintenance roof system with water-shedding performance.
  • Storm driven engineering design is proven throughout the world.
  • Includes the stringent Miami-Dade Approval.

Tile Roofing System Is Made of Lightweight High-strength Steel

Roser Cleo Tile

Roser Cleo Tile

The Roser Cleo Tile will give your home a fresh and radiant appearance while leaving you in the comfort of protection that only a stone-coated steel roof can offer. The beautiful appeal of classic tile with the performance of lightweight high-strength steel, resistant to fire and hurricane-force winds, is an ideal choice for any homeowner.

The roofing system includes:

  • Clear acrylic over-glaze protective coating
  • Roofing granule coating
  • Adhesive basecoat
  • Protective surface coating
  • Aluminum/zinc coating
  • Commercial-grade steel core
  • Aluminum/zinc coating
  • Protective surface coating

The Stone Coated Steel Roofing System, manufactured by Roser, offers the advantage of high-strength steel with a look a variety of traditional and innovative architectural styles. When compared to asphalt shingles and concrete roofing products, which can weigh 350 to 1,000 pounds per square, the Roser Stone Coated Roofing System, at only 150 pounds per square, effectively reduces the overhead weight on the house structure. This provides for a much safer building during an earthquake, fire or a hurricane. While the standard shingle and shake roofs naturally deteriorate over time, the Roser Roofing System will continue to maintain its beautiful appearance and requires the least amount of maintenance in the roofing industry. An eco-friendly Roser roof will increase the resale value of your home not only with its elegance, but also with its proven durability.

About the Roser Roofing System:

  • Installs direct to deck or over battens.
  • Stone surface resists fading and provides for a quiet roof.
  • Fastener design features a confirmed and a locking profile.
  • Low-maintenance roof system with water-shedding performance.
  • Storm driven engineering design is proven throughout the world.
  • Includes the stringent Miami-Dade Approval.

Copper-clad Stainless Steel Replaces a Tornado-damaged Roof at the St. Louis Airport

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.

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.

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.

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. “The tornado damaged less than 10 percent of the total roof, but that section needed to be totally replaced,” explains Jerry Beckmann, deputy airport director of Planning & Development. “That damage, plus the fact that the roof was almost 60-years old, influenced our decision.”

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’s 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.

COPPER AND STEEL

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—exactly the attributes desired by officials at Lambert-St. Louis International Airport.

“Copper-clad stainless steel is a great-looking material that can be fabricated for any roofing style. You can’t tell the difference between it and straight-up copper,” says Shane Williams, vice president of Civil Construction for Kozeny-Wagner Inc., the Arnold, Mo.-based general contractor awarded the public bid by the city of St. Louis. “It’s 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.”

Workers install CopperPlus batten-seam panels over a dome at Lambert-St. Louis International Airport. Stepby- step, the installation of CopperPlus is virtually identical to that of copper.

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.

The owners of Missouri Builders Service Inc., the Jefferson, Mo.-based roofing subcontractor, were attracted to the material’s lighter weight and easy solderability. “We 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,” notes John Kinkade, Missouri Builders Service’s vice president. “We 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.”

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. “The new skin will shine of raw copper like it did in the mid ’50s when the terminal was built,” Slay stated in a press release issued by the airport. “The roof will slowly transform in color again in time as this airport serves new generations in this region.”

WEATHERING NATURE’S WORST

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.

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:

  • Several 67-foot panels of copper-clad stainless steel were rolled onsite, then lifted and put in place by a crane to replace the ice-damaged roof at the St. Francis of Assisi Catholic Church, Traverse City, Mich.
  • In 2012, more than 30,000 square feet of copper-clad stainless steel were installed in the fascia and coping of the Trinka Davis Veterans Village, Carrollton, Ga., the nation’s first privately funded U.S. Department of Veterans Affairs’ VA facility.
  • In 2014, the material was selected for a 2,100-square-foot perforated sunscreen installation in San Francisco’s Mission Bay neighborhood, one of the most significant urban development projects in the U.S.

PHOTOS: MISSOURI BUILDERS SERVICE INC. AND LAMBERT-ST. LOUIS INTERNATIONAL AIRPORT

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Metal Roofing Resembles Shake, Slate and More

Quality Edge has launched Matterhorn Metal Roofing, which is made from steel and available in four profiles: Shake, Slate, Tile and Standing Seam.

Quality Edge has launched Matterhorn Metal Roofing, which is made from steel and available in four profiles: Shake, Slate, Tile and Standing Seam.

Quality Edge has launched Matterhorn Metal Roofing, which is made from steel and available in four profiles: Shake, Slate, Tile and Standing Seam. A two-year development process resulted in carefully crafted splits, cracks and grains that mimic each profile’s natural counterpart. The shake profile features 21 individual shake designs to enhance the natural overall effect. In addition, Matterhorn’s patented fourpoint fastening system conceals the overlapping metal panels on slate and shake. All profiles have been tested to withstand hurricane-force winds up to 130 mph.