Coated Glass Facers Bring New Performance Advantages to Polyiso Insulation

Photos: Owens Corning

Rigid polyisocyanurate (polyiso) insulation board is one of the most widely-used insulation products on the market today and is manufactured in various forms for use in wall, roof, and other building construction applications. The different types, classes, and grades of polyiso insulation board are defined by the classification system in ASTM C1289 “Standard Specification for Faced Rigid Cellular Polyisocyanurate Thermal Insulation Board” and may be classified by the type of facer or facing material used to manufacture the products.

Polyiso is a thermoset, closed-cell, rigid foam plastic insulation that is manufactured in board form (typically 4-foot-by-4-foot or 4-foot-by-8-foot sizes). Through a continuous lamination process, liquid raw materials that make up the foam formulation are mixed and in a rapid chemical reaction form a rigid and thermally stable polymeric structure. During manufacture, the facers or facing materials enable the manufacturing process by containing the viscous foam mixture as it is poured and cured into the rigid polyiso core.

After manufacture, facers or facing materials perform a number of key functions for the installation and use of polyiso products. At the jobsite, the specific type of facer or facing material can determine the insulation product’s compatibility with various substrates, which is an important consideration where installed as part of an adhered roof system. Once installed in a roof system, the facer or facing material can influence water absorption and water vapor transmission, which can be important characteristics in building envelope applications. In wall applications, polyiso may be used as a drainage plane to shed bulk water and with taped joints between adjacent boards can form both effective water resistive barrier and air barrier component. Facer or facing materials can positively contribute to the fire performance of the product and assembly, reduce air movement through the system, or provide for radiative properties. Finally, it should be noted that the same facer material is typically used on both sides of the polyiso board; however, different facer types may be used to meet specific project design and performance needs.

Facer Types

The three most common types of polyiso facers are aluminum foil, glass fiber reinforced cellulosic felt, and coated polymer-bonded glass fiber mat. The ASTM C1289 Standard contains classifications and descriptions for each facer type:

  • Aluminum Foil Facer (FF) is composed of aluminum foil that may be plain, coated and/or laminated to a supporting substrate.
  • Glass Fiber Reinforced Cellulosic Felt Facer (GRF) is composed of a cellulosic fiber felt containing glass fibers.
  • Coated Polymer-Bonded Glass Fiber Mat Facer (CGF) is composed of a fibrous glass mat bonded with organic polymer binders and coated with organic polymer, clay, or other inorganic substances.

Polyiso products as shown in Table 1 may also be manufactured with other facer types or facing materials such as uncoated polymer-bonded glass fiber mat (AGF), perlite insulation board, cellulosic fiber insulation, oriented strand board (OSB), plywood, and glass mat faced gypsum board. Depending on the particular project requirements, a certain facer type may offer specific benefits and the most attractive option for that application.

Coated Polymer-Bonded Glass Fiber Mat Facer

Coated polymer-bonded glass fiber mat facer (coated glass facer or CGF) is used in polyiso insulation products installed as part the building enclosure, including roof insulation, high-density cover board, and wall insulation products. Coated glass facers consist of multi-layer construction and a coating to impart a versatile weather resistant outer layer. CGF facers offer dimensional stability and resistance to water absorption. The glass fibers in the mat provide tensile strength and moisture resistance characteristics, making the mats an ideal solution for other product applications that require high levels of performance link flooring products, underlayments, asphalt shingles, roof membranes, ceiling tile, and other construction products (i.e., glass reinforced panels and industrial applications).

The CGF Manufacturing Process

For polyiso products, the CGF consists of a non-woven glass fiber mat as the substrate. The glass fibers that make up the mat are formed when minerals are batched together, melted in a large furnace, and extruded into strands through fine orifices in bushing plates. The fibers are mechanically drawn, cooled, and treated to impart the required handling and physical properties for the desired performance.

For non-woven applications, the fibers are chopped to the required length and sent to the mat forming line. The non-woven glass fiber mats (typically produced by a wet laid process on an inclined wire former) are impregnated with a synthetic water-based binder such as acrylic, urea formaldehyde, or renewable organic binders. The impregnated web is dried and cured in a direct gas-heated belt dryer. To produce the final coated glass facer, the rolled mat is coated with a mineral-filled latex coating to seal the mat. The coated mat is rewound and packaged according to individual product and customer specifications. After inspection, the mats are slit and wound in-line on cardboard cores in a turret winder.

The rolls of CGF are delivered to polyiso manufacturers where they are loaded into laminators to become the top and/or bottom facers of the finished polyiso insulation boards.

CGF and Polyiso Performance Benefits

Coated glass facers do more than hold the polyiso together as it cures; they add certain performance characteristics that can enhance the effectiveness of the final polyiso product. CGF as a material is noted for offering the following benefits for polyiso insulation:

  • Mold resistance
  • Enhanced fire performance
  • Excellent strength and durability
  • High moisture resistance
  • Excellent dimensional stability
  • Resistance to delamination
  • A reduction in knit line appearance

Since every type of polyiso product has its unique advantages and uses, choosing the right facer for the right application can have long-term impacts on the entire system’s performance and resilience. For example, some moisture is always present in our environment. CGF can provide added resistance to moisture absorption for polyiso products and help improve the performance and durability of the overall roof system.

Polyiso insulation products offer:

  • A high R-value per inch compared to other insulation products.
  • A certified LTTR value (roofing products).
  • The performance to meet today’s code required R-values while minimizing assembly thickness, and material and labor requirements.
  • Excellent performance in fire tests.
  • Ease of use and peace of mind, as polyiso products are designed for use in an expansive assortment of tested, approved, and code-compliant assemblies.
  • As a thermoset plastic, stability over a large temperature range (-100°F to +250°F) and can be used as a component in roof systems utilizing hot asphalt.
  • Versatility as a multi-attribute weather barrier product.
  • A continuous insulation solution to minimize heat loss through thermal bridges.

In summary, the combination of polyiso insulation and coated glass facers provide building owners and contractors with a solution that can meet thermal, moisture, and durability considerations. A wide variety of CGF polyiso products are available for specific applications in roofing or wall construction. Consult with a polyiso manufacturer for guidance on design and technical information for various insulation systems. Further information can be found at www.polyiso.org, the website of the Polyisocyanurate Insulation Manufacturers Association (PIMA), along with updated Environmental Product Declarations (EPDs), and technical bulletins for polyiso applications.

About the author: Marcin Pazera, Ph.D., is the Technical Director for Polyisocyanurate Insulation Manufacturers Association (PIMA). Dr. Pazera coordinates all technical-related activities at PIMA and serves as the primary technical liaison to organizations involved in the development of building standards. He holds a doctoral degree in mechanical engineering from Syracuse University and, over the course of his career, has worked in building science with a focus on evaluating energy and moisture performance of building materials and building enclosure systems. He has expertise in building enclosure and product manufacturing encompassed-research, testing, product conception and development, and computer modeling/analysis.

PIMA Issues Bulletin on Performance of Pentane Blowing Agents in Polyiso Insulation Products

The Polyisocyanurate Insulation Manufacturers Association (PIMA) recently issued a performance bulletin – Polyiso Insulation’s Low-GWP Blowing Agent Solution – highlighting the polyiso industry’s use of and the benefits provided by the pentane blowing agents used in polyiso formulations.

Closed-cell foam insulation products such as polyiso are manufactured with captive blowing agents. The blowing agents are primarily used to increase the final product’s thermal resistance or R-value. Polyiso products are manufactured using pentane or pentane blends. Pentane is a hydrocarbon with zero ozone depletion potential (ODP) and low global warming potential (GWP).

More than 20 years ago, the polyiso industry transitioned to pentane blowing agents after years of research and development. These pentane products replaced formulations using CFCs and HCFCs, which are no longer permitted for use in insulation products in major markets, including the United States and Canada.

“For more than 20 years, the polyiso industry has utilized pentane in product formulations,” said PIMA President Justin Koscher. “As a result of our industry’s efforts to eliminate the use of CFCs and HCFCs, the polyiso industry was recognized by the U.S. Environmental Protection Agency with the Stratospheric Ozone Protection Award for leadership in the phase-out of CFCs and exceptional contributions to global environmental protection.”

In closed-cell insulation products such as polyiso, the blowing agents are retained within the cell structure to provide long-term thermal performance. While closed-cell insulation products can exhibit an initial drop in R-value due in large part to the diffusion of air into the foam, all polyiso insulation products are tested to determine an aged R-value. Insulation products manufactured without captive blowing agents (e.g., expanded polystyrene, fiberglass, mineral wool) result in lower R-values per inch. Therefore, these products must be installed at greater thicknesses to equal the high R-value of polyiso insulation.

“Many states have, or are in the process of, instituting measures to eliminate the use of hydrofluorocarbons (HFCs) which are significantly more potent in terms of their contributions to global warming,” added Koscher. “Understanding a product’s impact on the environment, such as GWP, is a factor many designers are taking into consideration as they make product selections.”

PIMA’s performance bulletin can be found here.

For more information, visit www.polyiso.org

PIMA Launches Redesigned Website to Promote Benefits of Polyiso Insulation

The Polyisocyanurate Insulation Manufacturers Association (PIMA) announced the launch of its redesigned polyiso.org website. With an updated layout, content and features, the website now offers enhanced navigation that is accessible across all device platforms. 

“As an important resource for technical details and educational tools about polyiso insulation and its applications on roofs and in walls, an easily navigable website is critical, whether you’re accessing it from a computer or a hand-held device,” said PIMA President Justin Koscher. “Our members rely on the technical information found on our site and regularly send their customers to it. With a new layout and organization, we believe the updated polyiso.org site will help expand the knowledge of architects, consultants, building owners and roofing contractors.”  

The website features a variety of resources that include:

  • Building Codes: Details and fact sheets about building codes at the state and national level in the United States and in Canada.
  • Applications: Information about the application of polyiso insulation on commercial and residential roofs and walls.
  • Technical and Performance Bulletins: More than 35 technical and performance bulletins with up-to-date technical and industry information about the performance characteristics of polyiso insulation.
  • CEU Education Courses: A number of AIA CEU courses on the use of polyiso continuous insulation, reroofing and environmental product declarations.

For more information, visit www.polyiso.org

Non-Halogenated Polyiso Roof and Wall Insulation

Atlas Roofing Corporation adds ACFoam NH and EnergyShield NH to the company’s current product lines. These new non-halogenated polyiso roof and wall insulation products contain no halogenated flame retardants, providing additional environmentally friendly options to their product offerings of sustainable roofing and wall insulations for architects, designers and builders.

According to the company, ACFoam NH and EnergyShield NH product offerings are an ideal building envelope solution for projects that must meet strict specific environmental specification and customers seeking non-hal options. The Atlas NH product lines offer a variety of benefits, including:

  • Living Building Challenge “Red List” Free, with Declare label and product database listing
  • Contribute toward LEED v4 credit requirements
  • California Department of Public Health (CDPH) VOC emissions compliant 

“As a leader in polyiso manufacturing, we’re excited to introduce our non-hal technology and expand our ACFoam and EnergyShield roof and wall product lines,” said Greg Sagorski, Director of Technical Services of Atlas Roofing Corporation. “These new ACFoam and EnergyShield products provide the same great quality and performance needs customers expect, but with added benefits to meet more stringent environmental and sustainable building code goals.”

The following Atlas non-hal products are available:

  • ACFoam-II NH (also available in tapered)
  • ACFoam-III NH (also available in tapered)
  • ACFoam-Supreme NH
  • ACFoam-Recover Board NH
  • ACFoam Nail Base NH
  • ACFoam CrossVent NH
  • EnergyShield NH
  • EnergyShield CGF NH
  • Stucco-Shield NH
  • EnergyShield PanelCast NH

According to the manufacturer, all literature and product packaging of Atlas NH products will be marked with a non-hal icon for easy and visible distinction.

For more information, visit https://www.atlasrwi.com/.

Improve Commercial Roof Performance With Staggered Insulation Layers

Photo: Hunter Panels

Selecting the right components for a project can dramatically improve the performance and longevity of the overall building. In a commercial roofing project, the chosen insulation and the installation technique are critical to a building’s resilience and thermal efficiency.

From a physics standpoint, energy flows from a region of high to low potential (from warm to cold). Therefore, a significant amount of heat can leave a building through an inadequately insulated roof assembly during heating season (winter) and enter a building through an inadequately insulated roof assembly during cooling season (summer). A building with an under-insulated roof assembly may require more energy to compensate for these heat gains and losses.

The benefits of installing multiple, staggered layers of rigid board insulation have been well known for years. Industry authorities, including National Roofing Contractors Association (NRCA), Oak Ridge National Laboratory (ORNL), Canadian Roofing Contractor Association (CRCA) and International Institute of Building Enclosure Consultants (IIBEC), formerly RCI, Inc., have recognized these benefits; and contractors, designers and specifiers have followed the roofing industry’s long-standing recommendation for the installation of staggered insulation layers.

Using the optimal roof insulation product also will impact performance. Polyiso insulation offers key advantages in meeting stricter building standards and improving energy efficiency. Polyiso has a high design R-value compared to XPS, EPS, and mineral wool board. Lightweight and easy to trim, polyiso can be layered to reach the desired R-values without being cumbersome to install.

Why Are Multiple, Staggered Layers of Insulation Important?

In 2015, the International Energy Conservation Code (IECC) increased the R-value requirements for the opaque thermal envelope in many climate zones across the United States. As a practical matter, most roofs will require two or more layers of insulation to meet the local energy code requirements. In the 2018 version, the IECC was updated with specific installation requirements for continuous roof insulation. The 2018 IECC explicitly calls for continuous insulation board to be installed “in not less than 2 layers and the edge joints between each layer of insulation shall be staggered” (Section C402.2.1 Roof assembly). 

Figure 1. Multiple, staggered layers of insulation can minimize air infiltration and reduce or prevent condensation in the roof system.

Staggering the joints of continuous insulation layers offer a number of benefits:

· Increased thermal performance/reduced thermal loss: The staggered joints on multiple layers of insulation offset gaps where heat could flow between adjacent boards. The staggered approach to installing insulation reduces thermal bridging in the roof assembly. A fact sheet on roof insulation published by Johns Manville (RS-7386) notes that as much as 8 percent of the thermal efficiency of insulation can be lost through the joints and exposed fasteners of installations that use only a single layer of insulation.

· Air intrusion: When conditioned air enters the building envelope, often because of pressure gradients, it carries moisture into the roofing system. This moisture will undermine optimal performance. A peer-reviewed study on air intrusion impacts in seam-fastened mechanically attached roofing systems showed that air intrusion was minimized by nearly 60 percent when the insulation joints were staggered between multiple layers of insulation. (See “Air Intrusion Impacts in Seam-Fastened, Mechanically Attached Roofing Systems,” by By Suda Molleti, PEng; Bas Baskaran, PEng; and Pascal Beaulieu, www.iibec.org.)

Additionally, by limiting the flow of air and moisture through a roof system, staggered layers of insulation in a roof assembly can reduce and/or prevent condensation. The condensed moisture if allowed to remain and accumulate in the system can damage the substrate and potentially shorten the service life of a roof. A properly insulated roof can also prevent the onset of condensation by effectively managing the dew-point within the roof assembly. 

· Resilient roof assemblies: Staggered joints can reduce the stress put on a single insulation layer and distribute that stress more evenly over multiple, thinner insulation joints. For example, in an adhered roof system, the installation of multiple layers of insulation can minimize the potential for membrane splitting. In this system, the upper layer(s) of insulation can protect the membrane from potential physical damage caused by fasteners that are used to attach the bottom layer of insulation to the roof deck.

· Ponding water: Roof slope is often created through the use of tapered insulation systems. These systems offer an opportunity to stagger the joints by offsetting insulation layers and improve overall energy performance of a system. If the added insulation layer is tapered, the slope provided can improve drainage performance of the roof. Rainwater that does not drain and remains standing, collects dirt and debris that can damage or accelerate erosion of roof covering. Integrating tapered polyiso system with staggered joints into a roof’s design will not only improve the thermal performance but also can improve drainage and thus overall longevity of the system.

· Puncture resistance: Roof cover boards are commonly installed to provide a suitable substrate for membrane attachment as well as protect the roof assembly from puncture and foot traffic. When using products like polyiso high-density roof cover boards, the joints should also be staggered with the underlying roof insulation. This ensures the benefits discussed above are preserved in systems utilizing cover boards.

Installation Best Practices Are Keys For Success

A properly designed roof system that utilizes high-performance polyiso insulation products is a strong foundation (or cover) for energy-efficient and sustainable construction. However, the designed performance can only be achieved through proper installation. Implementing industry best practices such as the installation of multiple layers with staggered joints will optimize energy efficiency of the system and will help ensure that the roof system performs during its service life.  

To learn more about the benefits and uses of polyiso insulation,please visit the Polyisocyanurate Insulation Manufacturers Association website at www.polyiso.org.

About the author: Marcin Pazera, Ph.D., is the Technical Director for Polyisocyanurate Insulation Manufacturers Association (PIMA). He coordinates all technical-related activities at PIMA and serves as the primary technical liaison to organizations involved in the development of building standards. For more information, visit www.polyiso.org.

Carlisle Hosts Legislative Officials at Polyisocyanurate Manufacturing Facility

Carlisle Construction Materials (CCM) hosted Illinois State Senator Don Harmon and a team from his office on April 24, 2019, for a tour of its Franklin Park, Illinois, Polyisocyanurate (Polyiso) insulation manufacturing facility. Senator Harmon and his team observed the facility’s production of Polyiso insulation and met with several of the company’s employees. CCM invited these legislative officials as part of an ongoing effort to raise legislators’ awareness of the benefits that manufacturers bring to their communities and to discuss the challenges now facing America’s manufacturing sector. 

“As a U.S.-based manufacturing company, we were privileged to host Senator Harmon and his team. We are eager to discuss ways in which we can work together to create and sustain good-paying jobs for Illinois and support the growth of the manufacturing industry,” said Mike DuCharme, CCM’s Vice President of Marketing. 

“A changing economy and innovations in technology pose challenges for the future of the manufacturing sector in our state. I appreciated the time in the district and the chance to learn firsthand about this company and the industry,” said Senator Harmon. 

CCM is a member company of the Polyisocyanurate Insulation Manufacturers Association (PIMA), a national trade association representing Polyiso insulation manufacturers and suppliers to the Polyiso industry. PIMA advances the use of Polyiso insulation and is one of the nation’s foremost industry advocates for energy-efficient practices and policies. In addition, PIMA has been recognized by both the Environmental Protection Agency (EPA) and the Sustainable Building Industries Council for its advocacy and products. 

For more information, visit www.carlisleconstructionmaterials.com.



Polyiso Sump Panel Arrives Ready to Install

Hunter Panels Target SumpTo provide contractors with a faster and easier way to create roof sumps, Hunter Panels introduces its new 4-foot-by-4-foot Target Sump. The polyiso insulation panel is ideal for low-slope applications, ships flat, arrives ready to install and increases the slope around drains to ensure water will flow to the drain instead of ponding.

According to the manufacturer, the Target Sump’s coated glass (CG) facer provides improved dimensional stability, fire performance, resistance to mold growth and is compatible with all major roofing membranes and application techniques.

The new product is Hunter’s second sump panel, extending options beyond the company’s 8-foot-by-8-foot hinged target sump. Both sumps are factory assembled and pre-cut for easy installation. According to the company, they install much faster than cutting insulation on the job site, and eliminate waste, which reduces dumpster fees.

“At Hunter we do whatever it takes to serve our customers,” said Jason Greenleaf, technical & tapered design services manager for Hunter Panels. “Customers asked for a 4-foot-by-4-foot sump option, and we delivered with an innovative product that helps make installation easier, and projects more profitable.”

A Michigan Contractor Is Challenged to Recreate a Roof’s 40-year-old Mural

Kevin Clausen has faced a lot of challenges during his 30 years at Great Lakes Systems, a Jenison, Mich.-based construction company specializing in single-ply commercial roofs. But when he received a call several years ago from a Kent County official about an unusual upcoming project, Clausen knew he might be taking on a challenge unlike any other.

Artist Alexander Calder created the 127-square-foot red, black and white mural painted on the roof of the Kent County Administration building.

Artist Alexander Calder created the 127-square-foot red, black and white mural painted on the roof of the Kent County Administration building.

Kent County is home to Grand Rapids, Mich. To understand the challenge that Clausen was about to face, it’s important to understand a little Grand Rapids history. In the late 1960s, swept along by the tide of enthusiasm for urban renewal, the city demolished 120 buildings in its aging downtown core and built a new City Hall and County Administration building, surrounded by a concrete plaza. The new government buildings were designed by architects who were shaped by mid-century ideas of good urban design: sleek, boxy single-use structures, easily accessed by automobile and, therefore, providing ample parking. Pedestrians were something of an afterthought.

At about the same time, the National Endowment for the Arts initiated its Art in Public Places Program. There was general agreement in Grand Rapids that the broad plaza in front of the new buildings seemed empty and generally lacked visual interest. The city applied for a grant to support the funding of a monumental sculpture to serve as a focal point for its new plaza and selected renowned sculptor Alexander Calder for the commission. Two years later, Calder’s sculpture—bright red, 43- feet tall, 54-feet long, 30-feet wide, weighing 42 tons—took its place on the central plaza. It was named “La Grande Vitesse”, which roughly translates into “Grand Rapids”. For obvious reasons, the broad plaza has been called Calder Plaza—and has been the focus of controversy ever since.

The Calder sculpture at ground level on the plaza inspired another important work of art in the area. The flat, unadorned roof of the administration building adjacent to the plaza was drawing attention for the wrong reasons. It was easily viewed from the nearby taller buildings, including the new City Hall, and several city administrators thought some sort of added visual element was necessary for the space. Calder again was pressed into service and designed a large mural for the roof of the administration building. When it was completed in 1974, the 127-square-foot red, black and white mural painted on the roof of the Kent County Administration building was the largest Calder painting in the world.

A DURABLE ROOF

Fast-forward three decades and the aging modified bitumen roofing membrane, which supported the Calder mural, had weathered badly and was in need of repair or replacement. The challenge? How to repair the roof and still preserve the Calder mural. Given the deteriorated condition of the roofing membrane, a complete tear-off was required. Basically, the task at hand was to replace the canvas of a painting and recreate the painting, maintaining its original appearance.

Great Lakes Systems, Jenison, Mich., was challenged to recreate the Calder mural on a new EPDM roof after tearing off the modified bitumen roof on which the mural was originally painted.

Great Lakes Systems, Jenison, Mich., was challenged to recreate the Calder mural on a new EPDM roof after tearing off the modified bitumen roof on which the mural was originally painted.

The team at Great Lakes Systems has a long track record of doing work for Kent County, including the jail, juvenile facility and several libraries. Therefore, county leaders turned to Great Lakes Systems when they realized they need- ed a creative solution to repair their unique roof. Clausen says the county wanted to preserve the mural, but a long-lasting, durable roof was a top priority. “They definitely wanted a high-quality roof,” he says.

The project faced other constraints, in addition to the painted surface. The administration building is located in a prominent spot in the middle of downtown Grand Rapids, near the museum dedicated to former President Gerald Ford and adjacent to two major expressways. No interruption of normal activities could be allowed—either on the plaza or in the building supporting the Calder mural. And—perhaps most challenging—Great Lakes Systems was given three weeks to complete the project before the inaugural ArtPrize competition would take over much of downtown Grand Rapids. That meant the team would have two weeks for the roof installation, leaving one week to repaint the mural. This was less than half the time usually required for a comparable project.

For Clausen, one part of the project was easy. He had used EPDM membrane on a variety of prior projects for county buildings, and county officials had been pleased with the results, especially the balance of cost-effective installation and long service life. “We looked at other membranes, given the nature of the project, but we always came back to EPDM, given its 30-year plus lifespan,” Clausen notes. “If we have to paint again, that’s OK, but we don’t want to reroof.”

For this project, fully adhered EPDM, as well as insulation ad- hered to the concrete deck, offered two important benefits: a painting surface that would be appropriate for the repainted mural and minimal noise (compared to a mechanically attached system) so that work in the building below could continue as normal.

Great Lakes Systems used 60-mil EPDM to replace the aging modified bitumen system. The 18,500-square-foot roof was backed by two layers of 2-inch polyiso insulation, and the EPDM membrane was covered with an acrylic top coat to provide a smooth surface for the new painting. The top coat matched the three colors of the mural—red, black and white. The red was a custom tinted acrylic paint deemed to be compatible with the EPDM membrane and the black and white acrylic top coat provided by the EPDM manufacturer.

Great Lakes Systems took aerial photos of the existing roof, created a grid of the roof and—scaling the design from the photos—recreated the mural exactly, a sort of large-scale paint- by-number approach.

Great Lakes Systems took aerial photos of the existing roof, created a grid of the roof and—scaling the design from the photos—recreated the mural exactly, a sort of large-scale paint- by-number approach.

A BEAUTIFUL ROOF

The Great Lakes Systems’ team applied a creative approach to recreate the mural, adhering carefully to the original design. Because the county used the same colors on its street signs as in the original mural, color codes were available to allow the team to access colors that were identical to those specified by Calder.

Great Lakes Systems took aerial photos of the existing roof, created a grid of the roof and—scaling the design from the photos—recreated the mural exactly, a sort of large-scale paint-by-number approach. The most intricate part of the painting was the layout. Although some free-hand painting had to be done along several jagged edges, the team painstakingly followed the scaled grid and applied chalk lines to outline the original design on the repaired roof. Roller applications were used at the border of the chalk lines to define individual spaces and mark the stopping and starting points for the different colors. Following this “outlining” work, the large areas were sprayed to complete the painting process. The three-man painting crew finished the job with several days to spare, helped along with very good weather.

The roofing project was an informal jump-start toward reimagining uses for Calder Plaza. This past summer, Grand Rapids residents were given the opportunity to voice their preferences for new landscaping for the plaza, provide input for activities that would attract more families and children, and generally make the space more pedestrian friendly. The new proposals are generating excitement and enthusiasm in Grand Rapids. As the new plans become reality, the citizens of Grand Rapids can be assured the Calder mural and the roof supporting it will be doing their part to add beauty and shelter to Calder Plaza and its buildings for decades to come.

Roof Materials

60-mil EPDM: Firestone Building Products Co.
2-inch Polyiso Insulation: Firestone Building Products
Black and White Acrylic Top Coat: Firestone Building Products

PHOTOS: Great Lakes Systems

An Oceanfront Elementary School Poses Tough Problems, but a Coated Aluminum Standing-seam Roof Passes the Test

Elementary school students sometimes find themselves staring out the window, but few have a view to rival that of the students at Sullivan’s Island Elementary School in Sullivan’s Island, S.C. The school is located on oceanfront property, and when it was time for the original building to be rebuilt, the site posed numerous challenges.

The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide.

The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide.

The original school had been built in the 1950s. It had been designed for 350 students and built on grade. The new school would have to be elevated to conform to modern building codes and service 500 students. The structure would not only have to withstand high winds, severe weather and a salt-air environment, but it also would have to fit into its surroundings. Many residents feared the larger building would look out of place in the cozy beach community. It was architect Jerry English’s job to figure out a way to make it work.

English is a principal at Cummings & McCrady Architects, Charleston, S.C., the architect of record on the project. He worked with a talented team of construction professionals, including Ricky Simmons, general manager of Keating Roofing & Sheet Metal Co. Inc. in Charleston, to refine his vision and bring it to life. English and Simmons shared their insight on the project, and they both point to the building’s metal roof as a key element in the project’s success.

CHALLENGING DESIGN

Cummings & McCrady Architects handles a broad range of commercial, institutional, religious and historic work—new construction and renovation. The firm had done a lot of work with the Charleston County School District over the years, including a small library addition for the original Sullivan’s Island Elementary School after Hurricane Hugo passed through in 1989, and it was awarded the new construction project.

The building’s foundation system had to meet strict regulations regarding resistance to storm surge. The building is elevated on concrete piers, which were topped with a 6-inch reinforced concrete slab. Metal framing was constructed above the slab. “With our building, we had to raise the underside of the structure almost 7 feet above the grade,” English recalls. “What we did is we built it a little bit higher than that so the underside could be left open and used for playground.”

For English, coming up with a design that would reflect the character of the local community was the biggest challenge. To achieve that goal, he broke up the building into four sections and spread them across the site with the tallest sections in the center. “We have four linked segments that transition down on each end to the height of the adjacent residences,” he says.

The roof was also designed to blend in with the neighboring homes, many of which feature metal roofs. “The idea of pitched roofs with overhangs became a strong unifying element,” English explains.

English checked with several major metal roofing manufacturers to determine which products could withstand the harsh oceanfront environment and wind-uplift requirements. “Virtually every one of them would only warranty aluminum roofing,” he says. “The wind requirement and the resistance to the salt air were what drove us to a coated aluminum roof.”

The majority of the panels were factory-made, but the manufacturer supplied the rollforming machine and the operator to handle the onsite rollforming of the largest panels.

The majority of the panels were factory-made, but Petersen Aluminum supplied the rollforming machine and the operator to handle the onsite rollforming of the largest panels.

The standing-seam roof is made up of 0.040-inch coated aluminum panels that are 18-inches wide. Metal trusses give the roof system its shape. English tapped the resources of roof consultant ADC in Charleston and the metal roofing manufacturer to iron out all the details. English wanted to avoid any cross seams in the metal roofing, so he worked with Dave Landis, the manufacturer’s architectural/technical sales manager, to arrange for the longest panels to be formed onsite.

The roof also includes two decks that serve as outdoor teaching areas. These sections were covered with a two-ply modified bitumen roof system and protected with a multi-colored elevated concrete paver system.

Another standout feature is the school’s entry tower, which is topped by a freestanding hip roof featuring curved panels. This roof was constructed with panels that were 12-inches wide. “We found other examples on the island where the base of the roof flares a little bit as a traditional element, and with the closer seamed panels they were able to get those curves,” English says. “It’s a refinement that’s a little different than the rest of the roof, but it’s the proper scale and the fine detailing pulls it together and sets if off from the main roof forms that are behind it.”

PHOTOS: Petersen Aluminum Corp.

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Project Profiles: Retail

Sierra Nevada Brewery, Mills River, N.C.

About 58,000 pounds of copper were installed on the brewery.

About 58,000 pounds of copper were installed on the brewery.

TEAM

Roofing Contractor: The Century Slate Roofing Co., Durham, N.C.
Architect: Matthew Galloway of Russell Gallaway Associates Inc., Chico, Calif.

ROOF MATERIALS

Approximately 423 squares of 1/2-inch-thick, 18-inch-tall by random width Unfading Green Slates were installed by hand on the project. This was close to 750,000 pounds of slate, or 375 tons.

About 3,000 feet of custom copper gutters and downspouts, conductor heads and 100 squares of painted standing-seam panels were fabricated, and pre-built copper clad dormers and decorative copper cornices were installed.

The project also included 35 squares of copper standing-seam roofing, 25 squares of soldered copper flat-seam roofing and 115 squares of copper wall cladding. About 58,000 pounds of copper were installed on the brewery.

Everything on the building is oversized and that meant everything had to be built to support the heavy structural loads and live loads from wind and mountain snow. The large roof faces called for 10-inch custom copper gutters. When you have gutters that large in the mountains of North Carolina you have to consider the extraordinary weight of the annual snow.

In addition to snow guards being installed on the slate roof, custom 1/4-inch-thick copper gutter brackets fastened the gutter to the fascia. It is typical on steel-framed construction, particularly on this scale, that the framing is out of square and there is widely varying fascia and rake dimensions.

Approximately 423 squares of 1/2-inch-thick, 18-inch-tall by random width Unfading Green Slates were installed by hand on the project.

Approximately 423 squares of 1/2-inch-thick, 18-inch-tall by random width Unfading Green Slates were installed by hand on the project.

However, these items should not appear out of square or have varying dimensions. Great care had to be taken to measure and custom bend onsite all the detail flashings so everything appeared perfect. This took many skilled craftsmen, a great deal of time and the absolute drive to provide the highest quality work.

Slate Manufacturer: Evergreen Slate Co. Inc.
Copper Fabricator: K&M Sheet Metal LLC
Supplier of Underlayment, Copper Sheets and Coil, Insulation and Nailbase Sheathing: ABC Supply Co. Inc.

ROOF REPORT

The new-construction project began in November 2013 and was completed in September 2015.
The team completed the slate installation so well that The Century Slate Co. was awarded the 2015 Excellence in Craftsmanship Award by Evergreen Slate for the project.

PHOTOS: The Century Slate Roofing Co.

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