Fire Resistance for Insulated Metal Panels

When it comes to understanding fire ratings for wall panels on buildings, one of the first things to overcome is incorrect information or misunderstanding that sometimes emerges around this topic. In an effort to achieve some greater clarity, let’s look at some of the basics of fire resistance ratings, particularly for insulated metal panels (IMPs).

Building Code Requirements

The fundamental reason that any wall needs to provide some degree of fire resistance is to allow people enough time to safely evacuate from a space or building in the event of a fire, or to prevent the spread of fire between defined areas or whole structures. Building and fire codes have been developed and adopted, in part, specifically to define the situations, building types, conditions and circumstances where different degrees of fire resistance are required to protect the public health, safety and welfare. Therefore, when looking at a specific building and the fire resistance ratings required, the applicable codes must be consulted and the proper determination made regarding the minimum fire resistance requirements for the different exterior and interior walls of that building.

Ratings-Based on Testing

The established means for knowing whether or not a wall meets a particular fire resistance rating is based on conducting a fire test in an independent laboratory. For IMPs, that means a manufacturer needs to submit full-size product samples to a laboratory such as Underwriter’s Laboratories (UL), which will then prepare and carry out the test according to standard, agreed-upon procedures such as ANSI/UL 263, “Standard for Fire Tests of Building Construction and Materials.” The procedures dictated by a standard such as this are intended to be the same for all similarly tested materials or products to determine the actual fire resistance rating for each. When the products are subjected to the prescribed heat and flame under uniform laboratory conditions, then they can be classified based on how well they performed. Some products, for example, may survive the test long enough to qualify for a 1- or 2-hour rating, while others may only qualify for a 30-minute rating before succumbing to the fire.

Urology Medical Office Building MBCI
The Urology Medical Office Building in Virginia Beach, Virginia utilizes 7.2 Insul-Rib® and CF Architectural – Horizontal insulated metal panels. View the product data sheets for these products for information on their fire resistance ratings.

Selecting Products

In creating or renovating a building, then, it is incumbent on the design and construction team to choose products and materials that have a proven, tested fire rating that meets or exceeds the building code requirements for the particular building at hand. If a manufacturer of IMPs has been identified ahead of time, then it may be possible to ask for evidence of the UL or similar test to prove that the selected product or assembly meets the code requirements. But many times, there is a need to first determine the requirements, and then look for the available products and manufacturers who can provide the needed fire resistance. Fortunately, UL maintains an online directory of all of the products that they have tested and certified. Their online certifications directory allows users to input selected criteria to search for specific result reports. Using this resource for IMPs, the UL Category Code of BXUV and the UL File Number of U050 should be entered to do a search. This will yield a summary list referencing the ANSU/UL263 test with a link to the BXUV.U050 test report for IMPs. There you will see under item 2: “Metal faced panels, nominal 42 in. wide by nominal 4 in. thick (for the 1 Hour Rating) nominal 7 in. thick (for the 2 Hour Rating) or nominal 8 in. thick (for the 3 hour rating) installed vertically or horizontally. Panels supplied factory double tongue and grove joint.” This lets the design and construction know that 1-, 2-, or 3-hour ratings are available depending on the thickness of the IMP and given that the factory joint is provided. Hence, the manufacturer can label their products accordingly.

By specifying and selecting the proper products that have been correctly tested and certified, then building code compliance is not only streamlined, the building will meet the inherent fire and safety requirements for the people who will occupy it.

For fire resistance information on MBCI panels, please review the product data sheets.

Combatting Thermal Bridging with Insulated Metal Panels

When using compressible insulation, say for instance fiberglass batt, consideration must be given to how that insulation is going to be deployed in the actual wall or roof. For instance, installers might place the insulation across the framing members and then smash it down with the cladding and run a screw through to the underlying structure. The problem here is that the insulation is rated with some R-value—and that R-value is determined by an ASTM procedure that also determines what its tested density is. So in essence, it’s ‘fluffy’ insulation.

One manufacturer’s insulation, however, might be thicker than another’s. The contractor is buying an R-value, not a density or a thickness. The insulation is tested to that R-value at whatever thickness and density¹ is needed to achieve it. Let’s say R-19 fiberglass batt is specified, but then it is put in an assembly and smashed down flat… now it’s not R-19 anymore; it’s now R-something else. That’s a thermal bridge—when the insulation’s R-value has been compromised.

Manufacturers have the ability to run long length panels that minimize the number of end joints. This continuity provides significant advantages over traditional insulated materials when designing for energy efficiency. This image illustrates the difference between fiberglass batting made discontinuous by compression between panel and framing members and the continuous insulation provided by insulated metal panels.

Unfortunately, thermal bridging is almost impossible to eliminate. In the example above, another choice might be to put it between studs. Except in this situation, the studs break the insulation. While it’s not pinched, the studs are separating it. Whether the studs are metal or wood, in either case it’s still a significant thermal short circuit or a thermal bridge.

Even with the highest quality insulation systems—insulated metal panels, for example—a joint is required. Building is not possible without putting neighboring panels together. Therefore, insulation is discontinuous. While it’s impossible to avoid thermal bridging, there are two requirements to ensure the building performs the way it needs to perform.

  1. Thermal bridging must be mitigated. In other words, the designer or installer has to try to eliminate as much of it as possible.
  2. If thermal bridging is unavoidable, it must be accounted for in some fashion, which usually means putting more insulation somewhere to make up the difference. This is called a “trade-off” and is allowed by most building energy efficiency codes.²

Why Insulated Metal Panels?

Insulated metal panels then are the best bet, because although the joint is a thermal bridge, in effect, it is not nearly as impactful as breaking a line of fiberglass with a stud or smashing the fiberglass between the panel and a framing member. In the illustration below, R-value doesn’t just vary at that point where the panel and the stud meet. The entire insulation line gets smashed and one would have to go some distance from the stud before the insulation returns to its normal, fluffy thickness. These issues need to be mitigated and accounted for.

assembled side joint
Continuous insulation is critically important to an efficient envelope design. Insulated metal panels, with their side laps designed for concealed fasteners, eliminate the possibility of gaps in the insulation and thermal bridges. Continuous insulation is important because thermal bridges and discontinuities introduced by compressing non-rigid insulations cause the in-place R-Value of the assembly to be less than the tested R-Value of the insulation used. This effect has become a focus in newer energy efficiency codes such as ASHRAE 90.1 and IECC.

Manufacturers such as MBCI and Metl-Span publish insulated metal panels as U-factors because the joint is tested as part of the assembly (both mitigating and accounting for the aforementioned issues). These values can be found on product data sheets and technical bulletins, such as Metl-Span’s Insulation Values technical bulletin, published January 2017.

References

  1. ASTM C 665 – 12, Standard Specification for Mineral-Fiber Blanket Thermal Insulation for Light Frame Construction and Manufactured Housing, Table 1, Footnote c.
  2. ASHRAE 90.1 – 13, Energy Standard for Buildings Except Low-Ride Residential Buildings, Section 5.6
  3. High Performance Green Building Products – INSMP2A (CEU)

Beauty and Braun: The Benefits of Mixing Insulated Metal Panels with Single-Skin Panels in Commercial Design

Commercial projects aren’t one size fits all. By bringing in metal panel products to suit the individual need, designers and architects can provide custom solutions for a variety of applications. Single-skin metal panels and insulated metal panels (IMPs), if used correctly, can together add both aesthetic and functional value to your projects.

While IMPs can provide superior performance with regard to water control, air control, vapor control and thermal control, you may sometimes find your project requires—from an aesthetic perspective—the greater range of choices available in single-skin profiles. Let’s spend a little time looking at some of the reasons behind the growing trend of specifying a combination of insulated metal and single-skin panels.

Benefits of Insulated Metal Panels

Insulated metal panels are lightweight, composite exterior wall and roof panels that have metal skins and an insulating foam core. Their much-touted benefits include:

  • Superior insulating properties
  • Excellent spanning capabilities
  • Insulation and cladding all in one, which often equates to a shorter installation time and cost savings

Benefits of Single Skin

Single-skin panels, on the other hand, with their expansive array of colors, textures and profiles, may have more sophisticated aesthetics. They can be used on their own or in combination with IMPs. It should be noted, too, that single-skin panels can—in their own right (as long as the necessary insulation is incorporated) —satisfy technical and code requirements, depending on the application.

Beyond aesthetics, when it comes to design options, single-skin products offer a wide range of metal roof systems, including standing seam roof panel, curved, and even through-fastened systems. As for wall systems, those may include concealed fastened panels, interior wall and liner panels, and even canopies and soffits, not to mention exposed fastened systems. Therefore, you have a wide range of not only aesthetics options but VE (Value Engineering) options as well.

Why Mix?

So, in what situations might the designer or architect choose to combine the two panel types? Let’s examine a couple of specific scenarios related to the automotive or self-storage worlds as a means of illustration. In both of these types of applications, it is not uncommon for the designer to recognize the importance of wanting to keep the “look” of the building consistent with branding or to bring in other design elements.

Coalville Wastewater Treatment Facility
The Coalville Wastewater Treatment Facility in Logan, Utah combines the insulated CFR panel with the single-skin Artison L-12 panel.

Single-skin panels can be used as a rain screen system in the front of the building or over the office area, and would provide the greater number of design options. In the rest of the building, designers can take advantage of the strength, durability and insulation benefits of IMPs. Although you could use one or the other for these examples, the advantage of mixing the two would be achieving a certain look afforded by the profiles of single-skin, while still adhering to stringent building codes and reducing installation time—which is the practical part of using IMPs.

Focus on HPCI IMP Systems

One great example of a current trend we’re seeing at MBCI is the use of the HPCI-barrier IMP system, along with single-skin panels. The High Performance Continuous Insulation (HPCI) system is a single system that is a practical and effective replacement for the numerous barrier components found in traditional building envelopes.

HPCI Insulated Metal Panels
The HPCI Insulated Metal Panel is quick and easy to install and provides an economical solution to conventional air, water, thermal and vapor control without sacrificing thermal efficiency.

A big benefit to using the HPCI system is that the barrier wall is already in place. In terms of schedule, the HPCI barrier system is typically installed by contractors who are also installing the single-skin system, eliminating the need for multiple work crews, and thereby minimizing construction debris and reducing the likelihood of improper installation. With a general lead time of four to six weeks for the HPCI and a week or two for the single-skin, the installation goes fairly quickly. Therefore, it appeals as the best of all worlds—a single system meeting air, water, thermal and vapor codes (ex.: IBC 2016, NSTA fire standards) plus the design flexibility of a single-skin rain screen product. (Note: The HPCI panel must be separated from the interior of the building by an approved thermal barrier of 0.5″ (12.7mm) gypsum wallboard to meet IBC requirements.)

Bottom line, HPCI design features and benefits include the following:

• Provides air, water, thermal and vapor barrier in one step
• Allows you to use multiple façade options while maintaining thermal efficiency
• Easy and fast installation, with reduced construction and labor costs

Conclusion

As designers, architects and owners are getting smarter about a “fewer steps, smarter dollars” concept and an increased awareness of applicable codes and standards, not to mention lifecycle costs, the trend towards maximizing the strengths of available systems will continue to grow. Whether the right choice is an IMP system, single-skin or some combination, the possibilities are virtually endless.

Fastener Compatibility with Metal Roof and Wall Panels

The installation of a new metal roof or wall panel on a residential home, business or commercial building takes care, precision and—of course—the right tools. Regardless of the structure, you’ll likely find that choosing the correct mechanical fastener plays a key role in the long-term performance, durability and efficacy of the project.

Many metal roof and wall panels, in fact, rely upon the use of quality mechanical fasteners to secure components to a structure. In order to guarantee a resilient and weather-tight attachment, it behooves the user to select an appropriately compatible fastener type for the specific metal construction, thereby ensuring expected benefits, such as energy efficiency, extended life cycle, and even lowering insurance bills for the owner. In other words, once the decision has been made to use metal building materials for your roof or wall project, the next step is figuring out how to hold it all together.

Know Your Fastener Options

Before selecting fasteners for the project, it is important for the designer or installer to understand the various materials and options available. Typically, this involves the following considerations:

  • What type of material and coating is appropriate?
  • What type of head do I need? Does it need to be painted?
  • Do I need a washer? If so, what material should I use?
  • Should I use self-tapping or self-drilling screws?
  • What thread count should I specify?
  • How long does the fastener need to be?
Many Types of Fasteners
The MCA provides a summary of the different types of fasteners in their technical bulletin, Fastener Compatibility with Profiled Metal Roof and Wall Panels.

Select a Fastener on the Basis of Material

Most fasteners are made from coated metal but both the type of metal and coating must be chosen on the basis of the materials the fastener is bringing together. Galvanic action between dissimilar metals can cause premature fastener failure and lead to leakage. Even stainless steel screws will corrode severely under the right (or actually wrong) conditions. In extreme exposure, sometimes the best option is to use galvanized screws and plan on replacing them at a later date with a larger screw once the zinc has been depleted.

Considerations for Self-Drilling Screws

Self-drilling screws have a drill bit built in and don’t require a pre-drilled hole. Although self-drillers save the installer the step of drilling a hole, they are not always a good idea. The available space between the back of the hole and the next physical restriction must be at least as big as the bit itself or the threads will not engage. Also, drilling a hole allows a quick inspection to ensure the hole is in the correct location and plies are aligned and parallel. Generally, self-drillers are used when going through thin gauge steel into thicker gauge steel and self-tappers are used when fastening two thin gauge plies.

Washers

Fasteners may be used with or without washers. While plastic washers help prevent leaks, they are not required on purely structural connections. When using washers, it is important to visually inspect the screw after installation to be sure they are properly compressed and not kinked. Exposed plastics generally degrade when exposed to ultraviolet light. Furthermore, use of neoprene washers may be prevented by restricted material lists, or “red lists.” Fastener heads themselves may be made of different materials than the rest of the screw, long-life ZAC heads being the most common example.

Fastener Profiles

Fasteners have different profiles. Flat or “pancake” screws are used when low profile installation is necessary and may have Philips, hex, or Torx sockets. Which socket to use is usually an installer’s preference based on accessibility restrictions. Another common feature is an over-sized dome beneath the head to encompass a larger washer. Also called shoulder screws, these screws are useful when thermal movement might distort the holes.

Colored Fasteners for Metal Roofs
Fasteners can also be colored to match the roof or wall panel.

Thread Count per Inch

Thread count per inch, or TPI, must also be considered. Most commonly, fasteners are installed through the thinner ply first and grip in the thicker ply, pulling the plies together. Therefore, TPI selection is usually driven by the thickness of the thicker ply. Generally, the TPI is close to the gauge of the metal for gauge steel and higher for plate and sheet.

Length

The fastener must also be long enough to fully engage all plies of material, plus the length of the drill bit in the case of self-drillers. Generally, this is rounded up to the next half or quarter inch. However, the longer the screw, the more torsional strain is produced during driving and in the case of very long fasteners, this can break the fastener or introduce wobble, leading to poor installation. Therefore, stainless steel with over-sized washers is often used for long screws for added strength and protection.

For More Information on Fastener Compatibility

To learn more about fasteners and their compatibility with different types of metal roof or wall panels, check out Metal Construction Association’s recently published technical bulletin, Fastener Compatibility with Profiled Metal Roof and Wall Panels.

A Storehouse of Storage Solutions

With more than an estimated 54,000 storage units spread across the U.S. in 2015, according to IBISWorld, and 2.63 billion square feet of existing rentable self-storage space in 2014, the self-storage industry is booming. In fact, U.S. storage facility revenue topped off at an estimated $29.8 billion in 2014, rising to $31 billion in 2015 and is expected to reach $32.7 billion in 2016. In this growing market, storage builders and facility owners face increased competition and must build and maintain more efficiently and effectively than ever. Metal panels can be a differentiator for this market, especially through multi-story and climate controlled storage facilities.

MBCI Self Storage
Southlake Self Storage in Weatherford, Tex. is a multi-story storage facility utilizing MBCI’s PBU, PBD and PBR metal panels.

Maximizing Sustainable, Rentable Space

Among the cladding and roofing materials available to build these specialized facilities, insulated metal panels (IMPs) are highly energy efficient, deliver a full weather barrier and can be designed without exterior wall framing. This boosts rentable square footage by eliminating exterior wall framing typically built with studs, batt insulation, and liner panels.

Made from 90 percent closed foam, encapsulated inside of two metal panels and impervious to water, IMPs offer a high R-value, which is a big benefit for all storage types, particularly cold storage facilities. Steel panel facings create a vapor barrier and provide long-term thermal stability, virtually eliminating off-gassing found with rigid board insulation. IMPs give design professionals the opportunity to design functional, attractive, sustainable storage facilities, and facility owners the opportunity to lower construction, operating, energy consumption, and maintenance costs throughout the life span of a building.

As an all-in-one air solution—delivering an air, vapor and water barrier with continuous insulation—building teams can strip down the multiple trades to one single application. This means there are no gaps or voids to sap thermal value, and no degradation by air or moisture. Furthermore, IMPs are the most efficient product available, providing an R-value of 7 to 8 per inch vs. the 4.5 for batt insulation, essentially doubling performance. So not only do building teams come away with a thermally superior product, but the IMP storage facility will meet increasing continuous insulation code requirements, such as those mandated by ASHRAE 90.1.

Of course, increasing rentable square footage is one of the biggest draws about IMPs for building owners as those extra four to six inches on the perimeter go straight to the bottom line.

A Modern Style for Storage

Evolving from the standard-looking, plain boxes, today’s storage facilities are taking on a more architectural look to better blend into the office complexes, residential communities and retail complexes surrounding them.

With a variety of high-performance coatings, colors, reveal joints and corrugated sheets with assorted patterns, IMPs offer a large selection of design options to architects looking to create these more trendy designs.

Metal Panels for Self-Storage Buildings
A-AAAKey Mini Storage in utilizes modern colors with 55,000 sq. ft. of MBCI’s Ultra-Dek® metal roof panels.

“The calculated use of smooth, concealed-fastener panels harkens to contemporary design styles with an eye toward the future,” states Ryan Rogers, managing partner, RHW Capital Management Group, Orange, Calif., in an Aug. 2016 issue of Inside Self-Storage. “This can create the perception of innovation and dynamism, communicating to customers that your facility is on the cutting edge of the industry and, as such, a successful leader.”

In order to capitalize on the design and performance options leveraged by IMP panels, architects are advised to integrate these systems from the project’s onset in order to maximize efficiencies and potentially take advantage of longer stands, greater distances and heavier steel gauges.

Multi-Level Storage Facilities

Moving forward, designers can expect to see an increase in multi-story storage facilities, particularly in urban areas, where building owners are being forced onto smaller lots.

Explaining the trend in a Sept. 2016 issue of Commercial Investment Real Estate magazine, Michael Haugh, CCIM, senior director of revenue management, Storage USA, Memphis, states, “Increased land costs have forced developers to build up, particularly in urban markets where land tracks of four or more acres necessary for single-story developments are nonexistent. In some cases, a multistory project can be built on as little as 1.5 acres.”

Or in regions where there is little space for new construction but a high demand for storage, like New York City, storage companies are renovating upward. For example, Stop & Stor partners with door and storage solution company, DBCI to convert existing buildings into high-end, multi-level storage facilities. Using existing building blueprints and outline unit placement, DBCI created a custom storage solution in a space that is both conveniently located and functional For more information, read “Urban Storage Units” in Metal Architecture’s Jan. 2016 issue.

Filling the Storage Niche

From multiple stories to designer-end architecture, IMPs are actively filling an important niche in the self-storage industry as a durable and aesthetic, all-in-one building enclosure solution.

Nice Curves! Stunning Architecture with Curved Roofing and Walls

Breaking away from simpler panels, more and more architects are experimenting with arched and curved metal roofing and wall panels to upgrade their designs. This enables designers to incorporate exciting elements like concave and convex curving, not as feasible with other cladding materials.

Combined with unique angles, increased edge finishing options, appealing gutter options and greater compatibility with shingle types, architects now have access to a greater assortment of mix-and-match options.

For example, at Owens Community College in Findlay, Ohio, a regal red, double-curved canopy crowns the curtainwall with 15,500 square feet of 22-gauge curved metal roof panels. Designed by Rooney Clinger Murray Architects, the structural roofing panel system, fabricated by MBCI, is ASTM tested for air infiltration and water penetration, and incorporates a 2-inch tall standing seam that was field seamed during the installation process. The contractor, Charles Construction Services, won the American General Contractors (AGC) Build Ohio Award for “New Construction Under $10 Million.”

Owens Community College
For Owens Community College, the Curved BattenLok® metal panels in red accentuate the arch of the campus, making it the focal point of the building.

Another noteworthy curved design example is the Central Los Angeles Area High School #9, designed by HMC Architects. “Metal enabled us to clad buildings of different geometries, including curved geometries, in one material, while also giving them a special appearance,” reported Kerstin Kohl, spokesperson for the project’s design architect, COOP HIMMELB(L)AU, in a Metal Construction Association case study, Steeling Art for Students.

Using CAD and BIM for Curved Metal Panels

For designing and fine-tuning curved metal creations, the latest CAD and BIM features are key tools for architects.

In creating the “geometry that has been freed from the relentlessness of the orthogonal layout,” as described by Mark Dewalt, AIA, principal at Valerio Dewalt Train, in a recent article in Metal Architecture magazine, New Trends in Metal Architecture, designers are using CAD in shop drawings to support unique façade fabrication.

“The use of computer design to warp and twist and perforate will give metal greater longevity, added Kevin Marshall, AIA, LEED AP BD+C, associate architect, Integrated Design Solutions.

Similarly, BIM software is further supporting enhanced compatibility with metal roof and wall designs with newer features such as automated light gauge steel wall framing work and the ability to more easily configure supporting structures, openings, complex L or T connections and service hole positions while providing photorealistic renderings so that the client can see exactly how their building will look once built.

West Haven City Hall
West Haven City Hall combines MBCI’s Curved BattenLok® in Copper Metallic with Artisan® Series and Flat Sheet.

Ensuring a Tight Building Enclosure with Curves

As with any roofing type, designing and installing a tight building enclosure for curved roofing and walls is essential for delivering a high performing building.

For starters, architects must choose an appropriate vapor retarder, especially in cooler climates and interior relative humidity levels of 45 percent or greater. Also, buildings with high humidity interiors and construction elements that may release moisture after the roof is installed–such as interior concrete and masonry, plaster finishes and fuel-burning heater– require special considerations when choosing vapor retarders.

With utility clips, some curved panels will lay tight to the wood deck, but if tin tabs are used to attach the moisture barrier to the wood deck, then they will need to be covered to prevent the tabs from rusting the back side of the panels. Similarly, plastic washers may not be the best option as they run the risk of impacting the panels, resulting in undesired aesthetics. Rather, peel and stick membranes are a preferred underlayment because they eliminate the potential of underlayment fasteners penetrating or dimpling the panels.

A Savvy Look for Design

Whether it’s wavy, circular or some other exciting soft geometric shape, curved metal roofing and walls open up all kinds of new design possibilities. Out of the box, literally, architects are actively producing exciting, eye-catching creations with these welcomed capabilities.

Design and Color Trends in New Metal Construction

Design and color trends in metal roofing products are not exactly black and white. In fact, a whole host of options are available when choosing textures and colors for new metal construction projects, depending on specific criteria. Some are practical, some are aesthetic—but all are shaping how designers are specifying metal products, coatings and paints. Let’s walk through a few of the top trends in the industry now.

More color options for coil coatings

Bright Color Options in Coil for Design
Through vertical integration, manufacturers are offering more color options than ever.

It used to be that coil options were limited to standard stock choices and availability was determined by the coil coaters. Now, with evolving industry strategies, such as NCI’s vertical integration, many more manufacturers are properly positioned to enter into the market with multiple color choices across multiple brands without as much deviation. This also allows manufacturers to quickly adapt to requests for custom colors—both internally or externally.

Ratings and regulations are leading to more energy-efficient choices

Moreover, color requests based on aesthetics and paint systems have evolved based on changing code requirements. For additional benefits, specifiers can turn to many rating systems, such as the Cool Roof Rating Council and ENERGY STAR®, as well as earn LEED points by having specific SRI (Solar Reflectance Index) values.

Much has changed over the past 10 to 15 years. For instance, the components industry has evolved from customers merely selecting colors based on preference to a more integrated approach accounting for aesthetics, cost and energy efficiency. Today, owners and architects are more likely to consider a color such as Solar White to save on insurance or receive tax rebates. Environmental considerations and regulations have changed the way customers purchase steel, incorporating such issues as unique regulations for different states and weather conditions, LEED points and reflectivity into the atmosphere.

Insulated metal panels used in higher-end architectural projects

Another design trend in the industry is a move towards insulated panels, mimicking what is typical in the aluminum composite material (ACM) world. High-end car dealerships are known for design with ACM. This includes blocked-off designs that can be elongated, can be different colors or have joints in different places. This application has been ACM’s primary wheelhouse for decades. Now that ACM manufacturers have entered into the insulated metal panel (IMP)  industry, more of the design community is considering a thinner, horizontal IMP. The intention is to replicate the appearance of an ACM panel, while reaping the major cost and insulating benefits of IMPs.

Depth of color and texture: the rise of metallic colors

Architecturally, more metallic paints are being used. Historically, metal panels were white, tan or Galvalume. The current trend has expanded to a wider color palette, including mica fluoropolymer. These metallic coatings give depth to the color, adding sheen and sparkle. In fact, there are actually metal flecks in the paint. Metal oxide-coated mica pigments offer up the metallic look and add to the durability.

 Signature® 300 Silver Metallic Color Design
Vasa Fitness in Lehi, Utah features MBCI’s FW-120 panel in Signature® 300 Silver Metallic paint.

What’s behind this trend? Designers are thinking about metal roofs in a whole new way. They are looking to leverage colors and properties of paint to bring out a unique architectural appearance not previously available.

Conclusion

Trends in metal construction are as broad as the choices of color and coatings. Whether a reaction to energy savings criteria or simply a desire of an educated consumer to bring new life to their project, it’s worth taking the time to investigate all your options when specifying your next metal project.

Spray Polyurethane Foam (SPF) Insulation on Metal Roof and Wall Panels

With building code compliance and sustainable building envelopes at the forefront in today’s marketplace, spray polyurethane foam insulation (SPF) applied to single skin metal roof and wall panels is an alternative to insulated metal panels with a manufacture-applied polyurethane foam core. SPF insulation improves a building’s energy efficiency and provides thermal, air and vapor barrier capabilities.

What Is Spray Polyurethane Foam (SPF) Insulation?

SPF insulation consists of isocyanate and polyol resin that is chemically combined and applied to surfaces using a spray gun. SPF insulation can be open cell or closed cell.  Open-cell foam provides insulation and air sealing for a building, but is water and vapor permeable. Closed-cell foam provides better insulation than open cell and also functions as an air barrier. Closed-cell foam differs from open cell in that it prevents water entry, minimizes moisture vapor permeability and decreases air leakage, making it the preferred insulation to apply to metal panels.

Spray Foam Insulation with Metal Panels
Spray Polyurethane Foam Insulation with Metal Panels. Image courtesy of Spray Polyurethane Foam Alliance

SPF insulation is well suited for use as interior insulation for metal wall and through-fastened metal roof panels. The traditional thermal insulation layer—one or two layers of batt insulation with a facer—has its intricacies; for example, compressed areas and difficulty taping seams at edges and penetrations for air barrier performance.  But because of SPF’s inherent physical characteristics and spray application method, SPF overcomes many obstacles.

8 Application and Safety Tips for SPF

Using SPF to fully insulate and seal a building with metal panels can have unintended consequences if the material characteristics and project parameters are not well thought out. The Metal Construction Association (MCA) recently conducted research with the Spray Polyurethane Foam Alliance (SPFA) and published their findings in a technical bulletin. It includes the following best practices and considerations for installing SPF.

Image courtesy of Spray Polyurethane Foam Alliance
  1. Utilize a certified foam spray technician to ensure the insulation meets the desired thickness, density and adhesion.
  2. Only apply SPF to clean, dry areas.
  3. SPF should not be used on standing seam metal roof panels because it may restrict the thermal movement of the panels, causing distortion.
  4. Follow a “picture frame” application technique, further detailed here, to prevent SPF from getting between girts and metal panels, causing deformation.
  5. Notify other contractors, including HVAC and electrical, to ensure necessary precautions are made.
  6. Follow building code requirements for fire protection because in some instances SPF may meet thermal barrier requirements.
  7. Prevent SPF chemicals from being drawn into a building’s ventilation system during and after installation. There may be a mandated wait time before other occupants can reenter the space.
  8. Consult with your metal panel manufacturer before applying SPF.

Read more recommendations and findings by the MCA by downloading their technical bulletin, Spray Polyurethane Foam Insulation on Interior Surfaces of Metal Panels, here.

The Benefits of Integrating Daylighting Systems with Metal Panels

When metal roofing and wall systems of insulated metal panels, or IMPs, are combined with integrated daylighting and electrical lighting systems (such as with skylights, windows and translucent panels) it can improve occupant wellness and overall building performance. Are you curious if the return would be worth your investment? Uncover the recent advancements in daylighting technologies, the benefits and how to measure your building’s success.

Advancements in Daylighting Technologies and IMPs

In recent years, IMP assemblies have seen significant improvements, including more effective seals and thermal breaks as well as better thermal performance.

A range of novel daylighting products and technologies have been introduced in recent years that aid in the deployment of natural illumination for a multitude of occupancies—maximizing daylighting effectiveness while also maintaining the envelope’s barrier and thermal performance. These tools include pre-engineered, integrated metal envelope and roof solutions with compatible curbless skylights, light tubes, pan-type prismatic skylights, automated dimming controls for lighting, motorized shades and other components.

One example of how new tools are replacing more traditional products is the use of domed and pan-type units with prismatic embossing, which refracts and directs two to four times as much illumination into the indoor spaces when solar incidence angles are more acute, such as in the early morning and late in the day. These prismatic elements also help eliminate “hot spots” and reduce glare and ultraviolet (UV) deterioration from daylighting.

Daylighting with Metal Roofing

Benefits of Investing in Daylighting

Overall, using the current crop of novel skylight products in combination with a highly thermally efficient base system of metal panel walls and roofing will reduce excessive solar heat gain as they reduce the electrical base load for lighting. Highly diffusing acrylic and polycarbonate lenses and spectrally selective glass openings are very effective for maximizing functional visible light indoors while inhibiting unwanted heat gain. Many of the skylight aperture designs block 85% of infrared (IR) and 99.9% of UV light, which also reduces the unwanted degradation of products and materials inside the buildings. Additionally, the new generation of skylights also optimizes solar harvesting because many of the lenses have a minimal effect on VT.

In this way, the use of skylights with metal roofing and IMPs can be an effective way to meet the requirements of IECC 2012 and state energy codes. The skylights reduce overall electrical loads without adding unacceptable levels of solar heat gain, and their small relative area means the overall roof U-values remain low.

How to Measure the Success of Daylighting

Building teams will encounter a number of key variables that help measure the effectiveness of proposed daylighting designs. The most common (and valuable) daylighting performance metrics in use today include the following:

• Daylight factor
• Window-to-wall ratio, or WWR
• Effective aperture, or ea.
• Daylighting depth
• Solar heat-gain coefficient, or ShgC
• Haze factor
• U-factor

Using the above tools and terminology, building teams can better assess the benefits of daylighting strategies with skylights, prismatic pan-type products and solar light pipes, among others. In particular, these are important for meeting the widely used 2012 International Energy Conservation Codes (IECC) and ASHRAE 90.1 as well as state energy codes and “reach targets” such as green building certifications, the Passive House standard and others.

How to Learn More

The use of building systems combining metal roofing with skylights and integrated lighting provide significant life-cycle performance. Much of this is due to the research and development behind the individual products and materials used for these applications.

For a more in-depth look at daylighting within the context of metal roof and wall systems, please refer to MBCI’s whitepaper, Shining Light on Daylighting with Metal Roofs, which showcases the strong rates of return of using integrated daylighting systems with novel prismatic optics and high-efficiency lighting on metal envelopes with good thermal and barrier performance.

Download the White Paper, Daylighting with Metal Roofs

How to Help Prevent Oil Canning

Oil canning is defined as the visible waviness in the flat portion of a metal panel.  Oil canning is a visual issue, not a weatherproofing or performance issue.  However, building owners will complain about waviness in metal panels on roofs, walls, and perimeter edge metal.  Edge metal and metal wall panels are more of a concern than low-slope metal panels because edge metal and wall panels are visible from the ground.  Steep-slope metal panels and shingles are also visible, so awareness of potential oil canning is important.

Oil Canning on a Metal Roof

What Causes Oil Canning?

Oil canning can happen when unwanted stresses are introduced at fasteners, clips, and over purlins and uneven substrates.  Over-driven fasteners, clips that are slightly misaligned relative to the clip/seam interface, and too much insulation between the purlins and panels can introduce these unwanted stresses.  A misaligned panel or edge metal clip, certainly after the seam or drip edge is crimped tight, will add stresses to metal panels and edge metal

Tips to Help Prevent Oil Canning

  1. Place clips correctly: Setting clips in the proper location for edge metal and metal panels (roof and wall) is critical.  The clip needs to fit into a panel seam without forcing the vertical seam out of plane.  The clip needs to be aligned correctly and sized appropriately to not compress the vertical portion of the seam.  Clips that secure edge metal need to be positioned correctly so that crimping the drip edge won’t twist or bend the edge metal.
    Although not highly visible, low-slope structural panels can oil-can at clip locations and where insulation is draped over purlins.  Compressed insulation at purlins can “push back,” adding stress to the panel and resulting in oil canning.
  2. Consider the roof color: Sometimes oil canning is inevitable.  The color of the metal or coating won’t really make a visual difference, but darker colors panels will heat up more in direct sunlight.  This may make oil canning worse in some cases.  However, striations and small ribs (which also add strength) may help prevent or hide oil canning.
  3. Choose a thick metal: Metal thickness matters, so specify metal that’s as thick as possible to avoid oil canning.  Thicker metals are stiffer, so they may resist deformation due to unwanted stresses.  This reduces the chance of oil canning in edge metal and wall panels, which are most commonly smooth-surfaced.

For more information on oil canning and its causes, see the Metal Construction Association’s white paper on the subject, which can be found at www.metalconstruction.org.

Consider these ideas on your next job.

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