Sealing the Deal: The Importance of Properly Sealing the Building Envelope Using IMPs and Single-Skin Panels

The primary purpose of a building’s envelope (roof and walls) is to protect the building’s interior spaces from the exterior environment and provide the desired exterior aesthetics. Whether choosing insulated metal panels (IMPs) for their superior performance or, instead, looking to the wide range of aesthetic choices available with single-skin panels—or some combination of the two—the common goal must always be to protect the building from the potential ravages of water, air, vapor, and thermal/heat. By ensuring proper installation of metal panels and, thereby, properly sealing the building envelope, problems can be mitigated, efficiencies maximized, and the integrity of the building protected.

Here, we’ll briefly consider the benefits of each panel, and some key considerations relative to their sealant needs and capabilities.

Insulated Metal Panels (IMPs)

IMPs are lightweight, composite exterior wall and roof panels that have metal skins and an insulating foam core. They have superior insulating properties, excellent spanning capabilities, and shorter installation time and cost savings due to the all-in-one insulation and cladding. In effect, IMPs serve as an all-in-one air and water barrier, and are an excellent option for retrofits and new construction. With their continuous insulation, roof and wall IMPs provide performance and durability, as well as many aesthetic benefits.

IMPs offer excellent R-value and improve energy efficiency to the building envelope.
IMPs offer excellent R-value and improve energy efficiency to the building envelope.

Generally speaking, because of the nature of the joinery, it is easier to get a good seal in place with IMPs given their relative simplicity (i.e., putting the two pieces together with the sealant). They require great attention, though, in terms of air and vapor sealing—aspects largely controlled by the installers on a given project. As an example, vapor sealing in cold climates or applications is critical to the overall soundness of a building. Consider the damage a building could incur if moisture seeps into a panel and becomes trapped; it if freezes, it could push panels out of alignment. This would result in not just an unattractive aesthetic, but a performance failure as well. In order to be effective, all sealant and caulking must be fully continuous.

Single-Skin Panels

Single-skin panels, alternatively, offer the advantage of an expansive array of colors, textures and profiles. They are also thought to have more “sophisticated” aesthetics than IMPs. Single-skin panels are available in both concealed fastener and exposed fastener varieties, and are part of an assembly. They can be used alone or in combination with IMPs, and as long as the needed insulation is incorporated, single-skin panels can meet technical and code requirements, depending on the application. Single-skin products offer a wide range of metal roof systems and wall systems as well.

Getting the proper seal on single-skin panels may require extra sealants or closures, and have more parts and pieces that have to come together to create the seal. However, when properly installed and sealed, they can provide excellent performance in their own right. Some key caveats include ensuring panel laps are properly sealed with either tape or gun butyl sealants, and carefully inspecting air and water barriers for proper installation as well as penetrations through the wall for sealing/fire caulking prior to panel.

In most cases, following the details for the most common conditions will give you a successful and high-performing outcome.

Regardless of the type of metal panel used, taking the time and effort to ensure the sealing and caulking details are properly handled, metal buildings can protect the built environment and provide long-lasting quality and performance.

What You Need to Know Before Installing a Skylight

The beauty of skylights can be a real benefit to the aesthetic value of a metal building project. Beyond looks, though, the proven benefits of daylighting are many: building occupant satisfaction from natural lighting, mold and mildew growth prevention and, of course, energy savings, to name a few. In fact, once the decision has been made to go with metal for the roofing material, a skylight is often a natural tie-in when it comes to sustainable design—for both form and function. In order to make the most of the design choice, there are a few key considerations to bear in mind during the specification and pre-installation phases of the process.

Types of Available Skylights

Two common types of skylights used with metal roofs are Light Transmitting Panels (LTPs) and Curb Mount Skylights. Both supply natural light into the building and provide similar benefits. LTPs, which are formed from a translucent material and come in many different panel profiles, in actuality, can be used not only in metal roofs but as an accessory for metal wall panels, too. One of the key benefits of LTPs is that the panel is formed so that it substantially matches the configuration and characteristics of the system into which it is installed, and therefore can work seamlessly with specific metal roof systems. Curbed (curb mount) skylights include a raised structure (“curb”) formed around the roof opening where the skylight will be attached. Curb skylights come in many shapes and styles.

In addition to the general “type” of skylight, another consideration is selecting the best orientation for the skylight—which we’ll look at next.

Skylight Placement, Orientation and the Climate Factor

Placement and orientation are some of the most important factors in getting the maximum benefit from skylights. During the planning phase, determine the best location to achieve optimal light and to avoid obstructions (such as HVAC, plumbing, electrical, and vent pipes) below the skylight.

Skylight
Skylights and Light Transmitting Panels supply natural light into the building as shown above.

In terms of getting the most out of the skylight from an energy-savings standpoint, climate and exposure are also key factors. For example, with a southern exposure, skylights provide an excellent level of passive solar heat during the colder winter months, while keeping cooling costs down during the summer heat. On the other hand, a skylight with a western exposure will increase cooling costs if the structure is in a relatively warm climate.

Installation Planning and Timing

Skylights can be installed during or after the roof has been installed, but it is in the best interest of the project to plan for a skylight from the early stages of the design phase in order to best accommodate and prepare for the addition of the skylight.

Safety Concerns

Skylights and LTPs should be guarded to protect from fall through the use of metal railing, nets or some other method of protection.

Responsibility and Compliance

Last but certainly not least, it must be stated that it is the user’s responsibility to ensure that the installation and use of all light transmitting panels comply with State, Federal and OSHA regulations and laws, including, but not limited to, guarding all light transmitting panels with screens, fixed standard railings, or other acceptable safety controls that prevent fall-through.

For additional information about skylights for metal roofs, please contact MBCI at (877) 713-6224.

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