CONTINUING EDUCATION

BREAKING THE RULES

OF BORING ROOFS Presented by: Innovative Products NEW IDEAS TAKE ROOT UP TOP

LEARNING OBJECTIVES

At the end of this program, participants will be able to: 1. Understand the basic components of roofing systems. 2. List the testing and standards requirements for commercial metal roofs. 3. Identify the energy efficiency and sustainability attributes of a metal . 4. Describe the benefits of alternative uses for flat commercial roofs. 5. Explain the challenges and solutions to selecting materials that will compliment roof top spaces on commercial buildings.

CONTINUING EDUCATION

CREDIT: 1 LU COURSE NUMBER: ARapril2015.1 Use the learning objectives to focus your study as you read this article. To earn credit and obtain a certificate of completion, visit http://go.hw.net/ AR415Course1 and complete the quiz for free as you read this article. If you are new to Hanley Wood University, create a free learner account; returning users log in as usual.

Photo courtesy of Bison Innovative Products

By Andrew Hunt

GETTING THE LOWDOWN ON Metal roofing has gone through a transforma- THE ROOFTOP tion in the past ten years. Historically, metal roofing was flat, bland, and relegated to barns Designing commercial roofs can be akin to and utility buildings. Corrugated aluminum or designing stairwells. In a word: boring. Every panels were handy in areas of extreme fire building needs them, but really, what’s the danger, but for the most part were never hot point in dressing them up? But in recent sellers in the upscale design market. years, attitudes toward roofs have begun to change. Innovative designs in metal roofing This changed when metal roofing started have created a whole new way to think about being stamped into designs that, from street alternative materials in sloped roof applications. level, looked a whole lot like shingles or tiles. And if the roof must be flat, why let that space New colors and smart textures were developed go to waste? Exterior roof surfaces can now that opened up the design pallet for architects Metal roofing materials are often selected due to their durability and be transformed into all sorts of interesting in a whole new way. Once the illusion of low maintenance. Photo courtesy of Petersen Aluminum and attractive venues for meetings, social traditional sloped-roofing materials became One of the most appealing advantages of metal events, and even workspaces. When it comes available, the true advantages of metal roofing is their cost. Metal roofs can be an to roofing, modern architects are breaking the roofing started to take hold in commercial inexpensive option compared to traditional tile rules of boring. building settings. CONTINUING EDUCATION

or asphalt shingle roofing systems if you plan steel panels come in a wide range of gauges and damage from extreme weather events. on owning the building for any length of time. (thickness) and finish options. Consistently However, their good looks and durability come Sloped roofs with asphalt shingles generally though, corrugated steel panels are installed at a cost. Metal shingles are considered more of only last 12 to 20 years and can suffer from vertically with exposed fasteners. Architects a premium roofing product with more expensive regular wear and tear. In contrast, metal roofs today often choose corrugated steel panels as materials and higher installation costs than usually come with a guarantee of 40 years and roofing, siding, and accent options to complete corrugated panels or standing seam metal roofs. can last well beyond that. While the upfront the design of a commercial building. Stone coated steel tiles and shingles cost of materials may be more, investing in metal roofs can mean substantial savings in Rounding out the metal roof options are the simple maintenance and early replacement recently developed stone coated tiles and costs over the long term. shingles. These heavy-duty panels are an exclusive line of metal roofing because they are In addition to lower material costs over time, more durable and more aesthetically interesting labor costs are generally much lower for metal than traditional metal roof options. Heavy gauge roof installation compared to labor costs for steel panels are coated with crushed stone installing traditional roofing materials. This is and colored granules to imitate slate, cedar, due in part to the ease of installation, thanks to or clay tiles. Durable in all weather conditions, innovations in quick fastening systems and long stone coated metal tiles are able to withstand panel lengths. Panels up to 65 feet in length the impact of large hail stones and even resist can be ordered that provide visually seamless damage from wild fires, and hurricane force uniformity as well as rapid installation. Modern Standing seams are traditional metal roof designs with concealed winds. Stone coated metal tiles are also lighter systems also come with concealed fastening fasteners. Photo courtesy of Petersen Aluminum weight and less expensive than traditional clay systems and interlocking panel edges. More tiles. These attributes make stone coated metal traditional metal roof systems have exposed Standing seam tiles especially attractive in areas such as Dade fasteners that are equally easy to install, and Probably the most common style of metal County, Florida, where building codes require a panels up to 12 feet wide can make placement roofing is standing seam. These are vertically more aggressive line of defense for the home. and securing relatively quick and easy. installed panels with concealed fasteners. For Metal roofing materials aren’t as straightforward flat ranch-style buildings with simple design, WHAT’S IT MADE OF? as asphalt shingles, and selecting the right standing seam can be a very affordable option So now that we understand the four basic product to match the project takes a fair amount because installation is quick and easy and panels types of metal roofing available, let’s look of knowledge. While there are many details to can be milled to long lengths and healthy at material options. A large part of taking consider, the three biggest decisions to make widths. However, costs can rise quickly with advantage of the durable nature of metal before selecting a metal roof are style, material, more complicated designs. Dormers, skylights, or roofing is to understand the type of and finish. other penetrations and multiple slope changes used, gauges, and finishing. Although require additional hardware for installation and has been used for roofing since Roman times, METAL ROOF STYLES can slow down and complicate the construction today aluminum and steel are the most common Similar to traditional roofing materials, metal process. Extra time on the jobsite increases costs types of metal used and either can be ideal roofing is classified as either structural or and, unfortunately, also increases the risk of depending on budget, location and expectations. non-structural. Structural metal roofing attaches error, which can lead to potential quality issues Steel directly to purlins or lathe boards and does not down the road. require any sort of solid support beneath it. Metal shingles Mix iron, a little bit of carbon, add some nickel Non-structural metal roofing requires a solid or manganese for flavor, shake well and bake at substrate beneath it, typically plywood, oriented When looking for a more upscale option than around 2500 degrees Fahrenheit, and you get strand board, or a metal roof deck. There are metal roofing, painted metal shingles can offer steel. For metal roofing, steel has been the go-to four basic styles of metal roofing. While the curbside appeal that rivals traditional asphalt material since the mid-1800s, when corrugated durability, metal, and finish options are generally shingles, cedar shakes, slate, and clay tiles. These steel panels started gracing mills and industrial available in all four styles, the biggest difference shingles are horizontally-installed interlocking shops. But, while ideal for utilitarian purposes, between these styles is cost. metal panels attached with a concealed fastener simple corrugated steel panels had several faults. system. Metal shingles are in the architectural Corrugated panels classification, meaning they are thicker and can One of the most troublesome faults was that early steel roofing panels rusted quickly The most iconic example of metal roofs is the be used to create a three-dimensional look. when exposed to rain and snow. Even when corrugated steel panel. From chicken coops to Unlike corrugated steel, metal shingles are galvanized, any scrape or dent would expose shotgun shacks, corrugated panels have been generally made from higher quality materials the steel (specifically the iron component) and mainstays in easy to install, durable, and low and can have more durable coatings and color oxidation would set in. Over time though, cost roofing options. Over the years though, options as well. Because of the concealed improvements in the manufacturing of corrugated steel panels have improved to be fastener system, metal shingle roofs are generally steel made it stronger and more durable. more durable and fashionable. Today, corrugated more water resistant and suffer less from rust CONTINUING EDUCATION

DURABILITY BY THE NUMBERS like when it is galvanized to steel) and usually has higher levels of recycled material than When it comes to understanding the strength of a metal roof system, it is important to know that the type and style of metal roof specified meets or beats local and state building codes. In coastal communities where hurricane force winds traditional steel. can bring both gusts and uplift, metal roofs must be approved to several standards, which include: On the down side, aluminum is softer than steel • The American Society for • Underwriters Laboratories (UL) • UL 1897 Uplift Tests for Roof and tends to be more brittle. Also, aluminum Testing and Materials (ASTM) 580 Tests for Uplift Resistance of Covering Systems. Similar to UL E1592 Standard Test Method Roof Assemblies. This standard 580, UL 1897 specifically looks at is a poor choice if the builder is specifying a for Structural Performance of is used to determine the uplift pressure differences within the metal roof to protect against wild fire, because Sheet Metal Roof and Siding resistance of roof assemblies structure during uplift tests. Using it doesn’t have a Class A fire rating right out of Systems by Uniform Static Air including the roof deck and roof differential air pressure sensors, the box; however, with the proper underlayment Pressure Difference. This standard covering materials. It is applicable the entire roof assembly is eval- aluminum can get a Class A fire rating. Also, is used to evaluate or confirm to any type of roof assembly, uated including all components structural performance under so not only metal roofs need to such as base sheets, ply sheets, aluminum expands more than steel, so care uniform static air pressure adhere to the standard. Uplift slip sheets, membranes, etc., and must be taken during installation to make sure differences, or steady wind gusts is a very dangerous threat to insulation, if used. Supporting brackets and fasteners are specified to control expected in high wind areas. This structures in high wind areas roof decks are evaluated only with and manage expansion and contraction caused procedure is intended to represent because once the roof begins to respect to span conditions and the effects of uniform loads on fail, internal pressure differences physical properties such as gauge, by outside temperature fluctuations. One exterior building surface elements. within the building can quickly yield strength, grade, size, and/ final consideration is that aluminum is more overcome structural stability. or species of lumber and related malleable than steel, which can offer interesting factors which affect fastener and unique design options for architects looking attachment or bond strength. to create one-of-a-kind spaces.

Probably the biggest advancement in steel better than , which helps keep attics cooler, STEEL VS. ALUMINUM ROOFING roofing materials was the invention of modern reducing cooling costs. On the down side, So which metal type is better for roofing— galvanization techniques that significantly aluminum won’t help “heal” nicks and scrapes steel or aluminum? It depends on the project, increased the strength, appearance, and like zinc because once bonded to the steel, it location, and budget. This chart gives a quick longevity of steel. doesn’t flow like zinc. overview of how the two metals stack up to Galvanization, in simple terms, is a process in The third and most durable variety of galva- each other. which steel is coated with materials that protect nized steel is galvalume, which combines both the core metal from exposure to salt and water. coating materials to leverage the benefits of STEEL ALUMINUM There are three varieties of galvanized steel two protective metals on one form. Galvalume Cost Generally less Up to 20 percent available, but as we will see, one variety has is a mixture of zinc and aluminum and has more than steel taken over the market. generally replaced aluminized steel as a reliable option for roofing materials. Although more Malleability Less malleable More malleable for The first variety is the industry standard for expensive than traditional galvanized steel, creating interesting galvanized steel: zinc. Zinc works as a sacrificial galvalume coating offers more protection in design features coating on the surface of the steel to take the most environments cases, is easy to get, and Fire Class A fire-rating No Class A abuse of the elements. As the zinc coating can be ideal for steel roof options where quality protection fire-rating; weathers, it creates a barrier to further protect and durability matter. Similar to galvanized lower melting the steel core. Over time, this barrier can steel, galvalume comes in different grades, the point than steel actually “heal” minor surface scrapes because most common being AZ (aluminum/zinc)-50 or the zinc will flow into these areas. In general, Weight Heavier than Lighter than steel AZ-55, which are the same heavy duty grade as the heavier or thicker the zinc coating is, the aluminum G-90 standard galvanized steel. longer it will last and the better it will protect but still lighter the steel core. Galvanized steel is rated by the Aluminum than traditional amount, specifically the weight, of zinc applied asphalt shingles The other common metal for roofing is to a steel surface. Heavy duty galvanized steel Costal More susceptible Highly durable aluminum. Unlike steel, aluminum is naturally for roofing is rated as G-90, which means it has durability to damage against saltwater non-corrosive and durable, and so it does 90 ounces of zinc per square foot. Galvanized from saltwater not need galvanization or a metal coating steel is also available in G-40 and G-60 weights. to improve its performance. Heavier gauge Toe-to-toe More durable Less durable Aluminized steel is the second variety of aluminum is especially durable in coastal areas toughness than aluminum than steel galvanization. Developed about 60 years ago, where saltwater and spray can quickly pit, mar, steel is coated with aluminum instead of zinc, and deteriorate traditional steel. which offers two advantages. One advantage AND THE REST… Lighter weight than steel and traditional is that aluminum weathers better than zinc shingles, aluminum roofing is often an and does not corrode in coastal areas where You can’t really talk about metal roofs without attractive option when installing on top of an salt spray is common. The second advantage mentioning some of the other metals used. existing roof because the additional weight is is that aluminum naturally reflects sunshine Copper, of course, remains a favorite and minimal. Also, aluminum reflects heat well (just demands a premium price. Copper has been CONTINUING EDUCATION

used to build roofs on buildings since Roman QUIZ times. Literary buffs may recall the castle in Denmark that is the setting of Shakespeare’s 1. Which of the following metals is most commonly used to coat steel and What is the most common coating applied to the play Hamlet. The castle still has the same surface of steel create a protective barrier? copper roof it had in 1603, now an aged patina a. Cobalt b. Copper green. Today, special clear acrylic coatings can c. Zinc d. Nickel be painted onto copper to help it keep its brassy shine, but many clients, mostly in luxury 2. Why is Aluminum is a preferred choice over Zinc for roofing in coast situations? residential settings, prefer to let the copper age a. It keeps its glossy finish in the bright sun. b. It resists corrosion from salt spray. naturally to match aesthetic design elements. c. It weathers to match aged exterior. d. It is easier to find in coastal areas. Historically, lead was used to build roofs, such as the roof on Notre Dame Cathedral in Paris, 3. Which of the following is not a benefit of polyvinylidene fluoride resin (PVDF) coatings? France. However, lead is no longer an option a. Exceptional protection against UV rays. b. Protects against salt spray. due to health concerns. c. Protects against extreme weather events. d. They are made from recycled content. Other popular roofing metals are 4. Why is the solar reflectance (SR) rating for important when designing a cool roof? (an of steel mixed with chromium), and a. The higher the SR rating, b. The lower the SR rating, titanium, which is more corrosive-resistant than the better the roof is at reflecting heat. the better the roof is at reflecting heat. aluminum. From a cost standpoint, however, c. SR ratings have no impact d. The more heat absorbed into the building, copper is the only metal specified on a regular on cool roofs. the higher the SR rating. basis, and even then it is often out of the price range of commercial projects that aren’t 5. The term albedo in roofing is defined as: specifically trying to capture a historical look a. A color on the light spectrum. b. A high solar reflectance. and feel. c. An increase in worker productivity. d. An environmentally sustainable adhesive.

6. Which of the following does not break down paint exposed outdoors? a. High pressure b. Intense UV (sunlight) c. High temperatures d. High humidity This article continues on http://go.hw.net/AR415Course1. 7. According to the U.S. Environmental Protection Agency, rooftop gardens in commercial applications can greatly Ä reduce this effect: Go online to read the rest of the article and a. Urban Heat Island b. Power Transference complete the corresponding quiz for credit. c. Hard Water Pooling d. Radiant Parallel

8. Which of the following is not an advantage for using an elevated tile grid flooring system? a. Easy to repair and replace tiles. b. Provides a cavity for running utilities like wiring, SPONSOR INFORMATION plumbing and lighting. c. Provides a noise barrier for people working d. Helps with water management on the top floor of the building.

Innovative Products

9. What is an advantage of using tiles rather than planks for roof decking? Create beautiful rooftop environments with modular a. Tiles are less expensive than planks. b. Tiles provide more traction for slick surfaces. decking systems by Bison Innovative Products. Bison c Tiles have a more consistent color d. Tiles are easier to replace individually, rather than adjustable deck pedestals support a variety of surface from each batch. deconstruction of an entire section. materials such as Bison Ipe Wood Tiles, pavers, stone tiles, and decks on joists. Customize the spaces 10. What can be put on a rooftop to utilize flat spaces? even further with Bison Cubes—handcrafted planters a. Gardens and Kitchens b. Putting Greens and Playgrounds and modular benches. c. Bars and Cafés d. All of the Above

Long-recognized as an industry leader in metal standing seam roofing products, Petersen Aluminum also offers exposed fastener panels, flush panels, composite wall panels and column covers. All provide the well-known Petersen quality and are available in PAC-CLAD® Kynar 500® finish in 38 standard colors on steel and 37 aluminum. Most colors meet LEED, ENERGY STAR and cool roof certification requirements. CONTINUING EDUCATION

and Hylar 5000, and both are readily available. with low SR and TE numbers. There are several The mixture of PVDF is critical for its success; contributing factors that influence SR and TE the most common blend is 70 percent resin and numbers, such as roof color (light or white 30 percent pigment or coloring. Once applied, colored roofs have higher SR values), material, the resin-heavy paint is thicker and generally and paint type. The key to a cool roof is to try smoother in appearance than other paint types and get the highest values from both in order and offers exceptional protection against UV to reduce the amount of heat the building has rays, extreme weather events, and salt. to manage and cool.

GREEN METAL The benefits of substituting a cool roof for a conventional one are many, especially in warm or Metal roofs offer one additional unique feature hot climates. According to the U.S. Department that can’t be understated: they can be very of Energy, cool roofs can reduce air-conditioning Paints for metal roofs can come in a wide range of colors, and even environmentally friendly and can contribute custom colors can be ordered. Image courtesy of Petersen Aluminum energy usage by up to 15 percent while also to many green building programs. From a creating more comfortable occupant spaces in FINISHES AND OPTIONS sustainable building materials standpoint, there areas without air conditioning. Because of the isn’t much comparison between metal roofs The final bit to understand about metal roofs reduction in energy use, there is a reduction and traditional asphalt shingles; metal roofs before specifying is the types and kinds of in carbon emissions from fossil-fuel generated pretty much win every time. finishes available. Aluminum is the only metal power plants, which can help reduce the speed roof type readily available without a finish, but Recycled content and impact of climate change. even then an extra layer is added for aesthetic Metal roofs can have 25 percent to 95 percent Another advantage of cool roofs extends purposes. Besides adding color, a solid coat of recycled content, depending on the material beyond the building and into the neighbor- paint can help provide a more uniform surface used. Regardless of metal type, they are 100 hood. A cool metal roof can help reduce for water flow, can shed dirt better, and (with percent recyclable at the end of their life cycle. the urban heat island effect. The urban heat special additives) can reduce the growth of When compared to most asphalt shingles, tiles, island effect is a well-documented phenomenon mold, fungus, and algae. and other roofing materials, metal roofs remove that occurs mainly in densely populated areas In most cases, a durable paint is applied directly tons of refuse from the building-related waste with little shade, sparse vegetation, and an over the metal while still in the factory to stream each year. abundance of paved streets and shingled roofs. ensure an even and complete surface coating. Heat builds up in these areas as dark, dense Cool roof and reduced energy use There are several grades of paint finishes avail- materials absorb and retain solar heat energy. able in nearly endless color combinations. Even Metal roofs are often called “cool.” Not hipster As the day wears on, this heat capture can custom colors can be ordered, although usually or new phone app “cool,” but scientifically increase street level temperatures by as much as at a significant cost. Of the most common paint proven to reduce heat transfer from solar 12 degrees Fahrenheit. varieties, acrylic and other synthetic polymers radiation and decrease climate-changing ROOFING MATERIAL THERMAL PROPERTIES are usually applied. These paints provide an emissions from power plants cool. Although for additional layer of protection to the metal building science geeks, they can be both forms SOLAR THERMAL coating above the core metal, and can also of cool. REFLECTANCE EMITTANCE increase the overall durability of the roof. It is The industry definition of a cool roof is Metal (unpainted) 0.60–0.80 0.04–0.10 important to remember that galvanized metal determined by two factors and how these coatings can be brittle and flake off if struck or Metal (painted) 0.10–0.75* 0.75+ combined properties affect temperature within bent, so painted coatings help retain, protect, Comp Asphalt 0.05–0.25 0.90 the building: and further seal the galvanized coating. Shingles • Solar reflectance (SR)—the fraction of Single Ply 0.70–0.80 0.85+ A step up from basic acrylics is a siliconized sunlight that is reflected, expressed in Membranes polyester paint that provides better chalking decimal form where the larger the number, resistance and helps the paint retain a glossy the greater the amount of heat energy Built Up Roofing 0.05–0.80 0.90 “like new” shine. However, over time ultraviolet reflected away from the building. Modified Bitumen 0.05–0.25 0.90 (UV) rays, acid rain, and extreme heat can break down the paint. The result is white chalking and • Thermal emittance (TE)—the efficiency Concrete/Clay Tile 0.20–0.70* 0.90 with which a surface cools itself by a dull, lusterless finish. *depending on color emitting thermal radiation, expressed in The most durable coating option commonly decimal form where the larger the number, This chart shows the SR and TE values for common roofing materials. available in retail stores is a fluorocarbon-based the faster the surface will cool. Note that the higher the values, the better the material performs in paint with polyvinylidene fluoride resin (PVDF) cooling the building. Basically, a roof assembly with relatively high added. Many manufacturers have adopted The increase in ambient temperature outside SR and TE numbers will effectively reflect solar this style of paint because it offers superior puts and even greater strain on commercial heat energy away and also shed or re-emit heat long-term protection from the elements. buildings cooling systems, driving up utility costs. Common trade names of PVDF are Kynar 500 energy back into the sky faster than materials CONTINUING EDUCATION

Cool roofs, on the other hand, work as natural DRESSING UP THE FLAT TOP shared common areas. Incorporating a rooftop albedos or solar reflective surfaces than can space can free up valuable square footage in So, metal roofs are a fine option for slopes, help mitigate heat island effect. Asphalt the trunk of the building and also provide for a but what about dressing up the flat roof? shingles have SR ratings between .05–.25, multi-use, indoor/outdoor location that many Today, utilizing the flat spaces on roofs can which means they absorb almost all the heat occupants find desirable. be both economical and easy to design. energy during the day, while painted metal Maximizing available space can offer incredible roofing can have an SR rating of .75 depending opportunities to enhance both the occupant on the color. experience and value of the property. As mentioned before, color can play an Traditional commercial buildings tend to have important role in solar reflectance, but it isn’t flat roofs. These are easier to design, work always so black and white. Modern paints used well for storing heating and cooling systems, for metal roofing can actually be engineered and can be the most economical option when to increase solar reflectance in a wide range of drafting a project. What is often forgotten with color options. Oven-baked ceramic paints with this approach, though, is that a considerable high resin levels prove to be very reflective and amount of usable square footage is sacrificed. have the added benefit of durability. Exposure Designing attractive, environmentally-friendly to high UV energy, high temperatures, and high and functional space on the roof is getting humidity are the three things that break down easier thanks to new technologies in easy to any paint exposed to the elements outdoors, install flooring systems. Rooftops no longer have to be barren gravel fields. Modern and modern metal roof coatings have proven decking systems allow for innovative and attractive functional to be more durable in these environments than There are many potential uses for a flat roof designs. Photo courtesy of Bison Innovative Products traditional roofing materials. spaces in commercial buildings. The possibilities range from simple to luxury. Gardens, putting Overall, the pros of specifying a metal roof can GARDEN PARTY greens, bars, cafés, outdoor kitchens, entertain- greatly outweigh the cons if the commercial ment areas (including outdoor movie theaters), One option for dressing up the rooftop of building project is looking to invest in long-term dance floors, running tracks, tennis courts, a commercial building is to create a garden. durability and energy saving options. and playgrounds are all fair game for a rooftop According to the U.S. Environmental space. Adding these amenities to a building can Protection Agency, rooftop gardens in provide many benefits for occupants, owners, commercial applications can greatly reduce Cool roofs, on the other hand, and the community at large. the urban heat island effect and also provide a bevy of other benefits, including: work as natural albedos or solar For the building owner or developer, utilizing a rooftop space can help maximize appeal while • Reduced energy use by absorbing heat reflective surfaces than can increasing the rentable floor space below. Many and acting as insulation for the building. help mitigate heat island effect. commercial buildings today include amenities • Reduced air pollution and like coffee shop spaces, work out facilities, and greenhouse gas emissions by lowering air conditioning demand. CASE STUDY • Vegetation planted on rooftops can Iowa City, Iowa Fire Station #4 remove air pollutants and greenhouse Located on a high-visibility site, the Iowa City Fire gas emissions through dry deposition and Station #4 project had high expectations to be a carbon sequestration and storage. functional municipal facility that would be visually • Enhanced stormwater management attractive and also environmentally sound. The 11,300 square foot facility is comprised of two distinct and water quality by filtering pollutants elements: the apparatus bay and the service/living area. from rainfall and reducing the amount of The apparatus bay features a drive-through design, stormwater runoff in the urban setting. which is very popular with firefighters. • Improved quality of life and biodiversity by With LEED Gold level aspiration in mind, environmental impact and sustainability were forefront in the design offering aesthetic value and habitats for process from the selection of materials and systems to many plant and animal species. the arrangement of the building. Architectural design for the project was provided by Rohrbach Associates PC, Rooftop gardens can also be used to Iowa City Fire Station #4 proved to be a perfect opportunity to incorporate Iowa City. produce food. Many state and municipal sustainable metal roofing in to a LEED Gold building project. Photo courtesy of Petersen Aluminum Approximately 18,000 square feet of PAC-CLAD material governments are now offering incentive in three different profiles were utilized to meet design programs to encourage new and existing objectives. The project included 13,815 square feet of 24-gauge Tite-Loc Curved, Tapered and Straight Panels;,2,520 urban commercial buildings to incorporate square feet of .032 aluminum PAC-750 Soffit Panels, and 1,600 square feet of PAC-3000 AP Aluminum Plate Panels. green roofs to help offset the initial costs The installation of all roof and wall panels was done by Modern Builders, Inc., Janesville, Iowa. The Tite-Loc Panels of construction. used to roof the apparatus bay were curved on-site. CONTINUING EDUCATION

GETTING IT ON THE LEVEL rooftop spaces. One of the big advantages of In addition, water management on elevated this style of decking is that it provides a cavity tile systems is easy. Rainwater and snow melt One of the key challenges to designing a for the installation of wiring, plumbing, lighting, flow through the tiles and into the building’s usable flat roof space is the flooring material. and maintenance under a modular roof decking drainage system. This decreases the chance of A watertight and well-insulated roof will have system. Also, repair and replacement of tiles is slip hazards due to standing water and ice while to be built and installed, but what goes on top easy and much less invasive than for plank style also allowing the roof’s water mitigation system of it for users to walk on and enjoy? Rooftop decking. If a tile gets damaged, only that one to work efficiently. ◾ spaces are very similar to traditional decks piece needs to be unlocked and removed rather as they are built using planks, stringers, and than the deconstruction of an entire section. shims that tie into the wall and structure. For expansive projects, more elaborate roof/flooring CASE STUDY systems have to be used that can create heavy DaVita World Headquarter, Denver, Colorado loads for the buildings and can increase labor costs. The inherent problem with traditional Across from Denver Union Station, DaVita’s new corporate headquarters is an iconic 14-story tall office methods is that they often require multiple building. When DaVita, a health care company that is penetrations into the roof, which increases the leading provider of dialysis services in the United the potential for water intrusion and poor States, decided to relocate to Colorado and build their thermal boundary management of the building headquarters, they followed their mission statement of incorporating a sense of community and care. This envelope. Fear of troublesome construction, vision extended to their employees, or “teammates,” cost overruns, and potential leak liabilities have and a main priority of the building design was to kept many commercial builders from even create a healthy work environment that could enhance collaboration and offer opportunities to relax, socialize, exploring the functional uses of rooftop spaces, The DaVita World Headquarters, located in Denver, Colorado, proved to be and exercise. but today there are alternatives to old school an ideal use of screw-jack pedestal tile roofing. Photo credit: © Brett Drury Architectural Photography, Inc installation practices. A 2013 recipient of the NAIOP Colorado Academy of Excellence 2012 Office Development of the Year award, the DaVita building broke the standards of traditional office buildings by using premium spaces, such as the top floor, to install a full-service kitchen and dining area with panoramic mountain views and the largest rooftop terrace in downtown Denver. The building features three separate outdoor terraces. The largest terrace is located on the 14th floor and stretches 6,000 square feet, offering trees, outdoor dining, comfortable lounge seating surrounding a fire pit, and spaces for employees to plant herbs for the kitchen and other foliage. This terrace also has a stunning view of the two largest peaks along the Front Range, Pikes Peak and Long’s Peak. Screw-jack pedestal support systems enable quick installation or Bison 2'x4' ribbed wood tiles set on screw-jack pedestal supports created both functional and aesthetic benefits to rooftop flooring but also allow for easy access to maintenance areas underneath. Photo courtesy of Bison Innovative Products the expansive outdoor spaces, and are prominently featured on the DaVita World Headquarters rooftop deck. The use of innovative roofing materials complemented the overall philosophy of the company and its desire that anyone working or visiting the building have easy access to fresh air. Elevated tile grid flooring systems supported on Whether working to spruce up a sloped roof with durable metal, or to expand the indoor square footage with gravity-based, screw-jack deck pedestals have innovative rooftop and terrace decking, breaking out of traditional roofing forms is easier and more affordable replaced traditional decking methods and have than ever before. overcome many of the potential challenges of

RESOURCES

Cool roof presentation UL1897 Iowa City, IA Firehouse #4 Case Study https://www.pac-clad.com/interactive-pdfs/cool-metal-roofing- http://ulstandardsinfonet.ul.com/scopes/scopes.asp?fn=1897.html https://www.pac-clad.com/case-studies/multiple-petersen-metal- presentation/files/assets/downloads/publication.pdf Cool Roofs—U.S. Department of Energy panel-profiles-highlight-leed-gold-fire-station/?media=1 Cool Metal Roofing—Cool Metal Roofing Coalition http://www.epa.gov/heatisland/mitigation/coolroofs.htm Green roofs—U.S. Environmental Protection Agency http://web.stanford.edu/group/narratives/classes/08-09/CEE215/ Cooling Urban Heat Islands—U.S. Department of Energy, Energy http://www.epa.gov/heatisland/mitigation/greenroofs.htm ReferenceLibrary/Cool%20Roofs/ Efficiency & Renewable Energy (EERE) WBDG%20Cool%20Metal%20Roofing%20Guide_Read.pdf https://www1.eere.energy.gov/buildings/pdfs/ ASTM E1592-05(2012), Standard Test Method for Structural cool_roof_fact_sheet.pdf Performance of Sheet Metal Roof and Siding Systems by DaVita World Headquarters Uniform Static Air Pressure Difference, ASTM International, West http://www.naiop.org/en/Magazine/2014/Fall-2014/ Conshohocken, PA, 2012, www.astm.org Development-Ownership/DaVita-World-Headquarters.aspx UL 580 DaVita Rooftop decking products http://ulstandardsinfonet.ul.com/scopes/scopes.asp?fn=0580.html http://www.bisonip.com/portfolio-items/5197/?portfolioID=5434