Concealed and Exposed Fastener Panels: What’s the Difference?
There’s no doubt about the merits of metal roofing systems. Durable, aesthetically pleasing, and incredibly long-lasting, metal panels offer many rewards to property owners across Montana. But did you know even the type of connection strategy used to fasten a panel has unique benefits?
Concealed and exposed fastener panels are the main types of connection strategies used for metal roofs, and each has unique advantages and challenges. Today, we’re breaking down the key differences between concealed and exposed fastener panels. At the end of this blog, you’ll be fully equipped to select the connection strategy that’s best for your roofing and siding needs. Let’s dive in!
What are Concealed and Exposed Fastener Panels?
The terms “concealed” and “exposed” refer to the type of fastening system each panel type uses. Concealed fastener metal roofing uses fasteners that are hidden beneath the roofing surface so you do not see the fastener. Conversely, exposed fastener metal roofs have visible fasteners. These fasteners directly penetrate the panel to secure it to the roof deck.
What are the Differences Between Concealed and Exposed Fastener Panels?
Due to the differences in connection strategies, concealed and exposed fastener panels have distinct benefits and obstacles. Your choice between these panel types depends on your goals and property needs. You’ll need to take into account each panel type’s unique characteristics when making a decision. Overall, the differences between the two panel types come down to aesthetics, installation, maintenance, and cost.
Aesthetics of Concealed and Exposed Fastener Panels
Concealed Fastener Panels
Concealed fastener panels hide the presence of screws that can disrupt the overall, cohesive look of a roofing system. The absence of visible fasteners helps create a smooth, uniform finish to onlookers, lending to this panel’s visual appeal. Buildings with contemporary architectural designs often opt for concealed fastener panels to create a sleek, stylish look.
Exposed Fastener Panels
The visible screws on exposed fastener panels don’t diminish their aesthetic appeal but do give them a more industrial, traditional feel. Some people choose exposed fastener panels for rustic or agricultural building designs, as the exposed fasteners lend to an overall honest, classic look.
Panel Installation Considerations
Concealed Fastener Panels
Installing concealed fastener panels requires close attention to detail, adherence to slope best practices, and trained skill. Firstly, concealed fasteners perform better on lower roof slopes, so considerations for this must be taken into account before selecting concealed fastener panels for a project. Secondly, each panel must be correctly aligned and measured to ensure that the fasteners are hidden and securely attached. Installers use clips or fasteners that attach to the underlying structure or the adjacent panels. This allows the panels to move slightly with temperature changes without causing damage. The precision required for this installation means you not only need skilled installers but also extra installation time. However, if done accurately, the end result is a clean, streamlined roofing appearance.
Exposed Fastener Panels
Exposed fastener panels are generally straightforward and quick to install. These panels are fastened directly through the panel and into the roof deck or frame below using screws. These screws remain visible on the surface of the panel, so there are no additional steps needed to conceal them. Because of this, this method does not require added technical skill or specialized tools as with concealed fasteners.
Maintenance & Upkeep of Panels
Concealed Fastener Panels
Concealed fastener panels have a clear advantage in maintenance and durability because of their design. The fasteners are tucked away under the metal sheets, shielding them from rain, snow, and sun. This protection means the fasteners don’t wear out as quickly. They’re less likely to rust or break compared to those on exposed fastener panels. Additionally, concealed fastener panels are better able to withstand the forces of thermal expansion and contraction compared to exposed fastener panels. Since the fasteners are not exposed to the changing temperatures, they are less prone to loosening, which often leads to leaks in roofs with exposed fasteners. Overall, this makes concealed fastener panels a more durable and low-maintenance choice, requiring fewer checks and repairs for issues related to the fasteners.
Exposed Fastener Panels
Unlike concealed fastener panels, the screws on exposed fastener panels can eventually need replacement. Because these screws are exposed to the elements, they experience more wear and tear. These screws typically have rubber washers at the base to help seal out water. But, over time, these washers can degrade, and the screws can loosen due to the natural expansion and contraction of the metal. This can lead to potential leaks over time. Because of this risk, exposed fastener systems often require periodic maintenance to retighten loose screws and replace worn washers to ensure the roof remains watertight.
Cost of Concealed Fastener Panels vs Exposed Fastener Panels
Concealed Fastener Panels
Concealed fastener panels typically come with a higher initial price tag. The materials often used in these panels are usually of higher quality (thicker gauge), lending to a higher price. Additionally, the installation process is more labor-intensive because of the precise placement and special equipment needed. Despite the upfront cost, the investment is worth it. As previously mentioned, these panels provide a tighter seal against harsh weather, significantly reducing the risk of leaks. Their robust construction also tends to have greater durability, which can mean fewer repairs and replacements over the roof’s lifespan. This can make concealed fastener panels a more cost-effective option over many years.
Exposed Fastener Panels
Exposed fastener panels are generally more budget-friendly at the outset. They require less specialized labor for installation, which can significantly lower initial costs. The installation process is also usually quicker, reducing labor costs even further. However, these cost benefits can be somewhat offset by increased long-term maintenance. As we mentioned earlier, exposed fasteners are more susceptible to the elements, which can lead to issues like corrosion or loosening over time. Regular maintenance is required to tighten or replace fasteners and ensure the integrity of the roof. This can add to the overall cost of upkeep.
Get Started with Great Northern Metal Company
Deciding between concealed and exposed fastener panels depends on your specific needs, budget, and aesthetic preference. If you’re ready to discuss which option is best for your project, reach out to us at Great Northern Metal Company. As Bozeman roofing experts, we’re here to provide in-depth advice and quality materials that fit your project’s demands. Our team goes above and beyond to understand your goals and specifications to ensure you’re matched with the best materials for your needs. Contact us today for a consultation or quote—let’s build something great together!
What Is Sealant for Metal Roofing?
Metal roof sealant helps seal seams, joints, gaps, and other areas where water or air could enter a roofing system. Most gun-grade sealants are applied from a tube and form a bead over or within a joint. Depending on the formulation, the material may remain permanently pliable or cure into a flexible seal.
For metal roofing, flexibility matters. Panels naturally move as temperatures rise and fall, so a sealant used at a moving joint needs to accommodate that movement without losing adhesion.
The location of the seal matters too. A product used at an exposed seam may need different properties than one placed inside a concealed joint.
Sealant also should not be treated as a substitute for proper flashing, fastening, or panel installation. It works as part of the roofing system, not as a fix for a detail that was built incorrectly.
What Is Butyl Tape for Metal Roofing?
Butyl tape is a preformed sealing material typically installed between two roofing components. Instead of applying a bead from a tube, the installer lays a continuous strip of tape along the joint before the materials are fastened together. That makes it especially useful at concealed laps and other locations where two metal surfaces come together.
Butyl stays flexible, which helps it maintain a seal as a metal building experiences normal movement. There are also expanding sealant tapes that serve a similar purpose while filling irregular gaps and accommodating movement within the joint.
Sealant vs. Butyl Tape
The simplest way to think about the difference is application.
Gun-grade sealant works well when you need to apply a bead into a seam, joint, or gap. Butyl tape works well when you need a continuous seal between overlapping or adjoining components.
One is not automatically better than the other. The roof detail determines which type makes sense.
Metal Roof Sealant vs. Butyl Tape: Which Should You Use?
Different roof details put different demands on the sealing product.
These are general guidelines. Always check the roofing-system requirements and the manufacturer’s installation instructions before choosing a product.
4 of the Top Metal Roof Sealants and Butyl Tapes
The right product depends on the joint, expected movement, temperature conditions, and whether the seal will be exposed or concealed.
Here are four options GNMC has tried, tested, and trusts so much that we chose to carry them at our shop.
Best for: Expansion joints, lap seams, and joints that need to accommodate movement.
EMSEAL AST Hi-Acrylic Sealant Tape is a self-adhering, open-cell polyurethane foam tape impregnated with acrylic-modified asphalt.
Unlike a standard flat tape, EMSEAL AST gradually expands after it is removed from its packaging. That allows it to conform to the joint and fill gaps along irregular surfaces. For metal roofing and metal buildings, that can be particularly useful around details affected by thermal expansion and contraction.
Why It Works Well With Metal Roofing
One of EMSEAL AST’s biggest advantages is its ability to move with the building. The tape conforms to contours and maintains a seal as metal panels expand and contract. It is designed to help keep out dust, air, wind-driven snow, and moisture through joint details.
It also does not dry out and become hard or brittle over time. Because the material remains compressed within the joint, it is designed to stay in place rather than squeeze out the way some caulks or butyl products can.
Its resistance to UV exposure, aging, and mildew also makes it well suited to demanding exterior applications.
Common Applications
EMSEAL AST can be useful for:
- Expansion and compression joints
- Lap seams
- Mechanically fastened joints
- Irregular gaps
- Metal building details where movement needs to be accommodated
It can also be used alongside several common building materials, including metal, plastic, wood, and concrete.
Interested in EMSEAL AST? Contact GNMC
Best for: Metal panel joints that need a permanently pliable, gun-grade sealant.
TFC BUTYL™ is a single-component butyl-based sealant designed specifically for strong adhesion to metal panels.
Its biggest distinction is that it remains permanently pliable. It does not skin over into a hard surface, which allows the material to continue moving with the joint after installation.
Why It Works Well With Metal Roofing
Metal panels do not stay perfectly still over the life of a building. Temperature changes create movement, and joints need a sealing product that can handle it.
TFC BUTYL remains flexible and moisture-resistant, which makes it useful for metal panel details where a rigid sealant would not be appropriate.
It also meets or exceeds AAMA 809.2 and is available in gray or white.
Installation Matters
Good adhesion starts with a clean surface. Before applying TFC BUTYL, the substrate should be dry and free from frost, oil, grease, incompatible coatings, or other contaminants that could interfere with adhesion.
The product is applied using a standard caulking gun and can be tooled after application if needed.
It is also worth paying attention to storage. TFC BUTYL should be kept in a controlled, dry environment below 75°F and used within 12 months of manufacture.
One other detail to know before choosing it: TFC BUTYL is not paintable.
Ask GNMC about TFC BUTYL™.
Best for: Seams, panel joints, and gaps that need a flexible cured sealant.
NovaFlex Metal Roof & Panel Adhesive Sealant is a single-component silicone sealant and adhesive commonly used as a seam sealant or joint filler in metal roofing and panel systems.
It is non-corrosive and non-sag, making it useful where contractors need a gun-grade product that will stay where it is placed.
Why It Works Well With Metal Roofing
Temperature range is one of NovaFlex’s standout characteristics. The product can be applied at temperatures from -20°F to 160°F and has a service temperature range of -40°F to 400°F.
That broad range is useful for metal roofing, where surfaces can experience substantial temperature swings.
NovaFlex also offers good adhesion to common building materials and can bridge gaps up to 3/8 inch. Its exterior weathering and aging performance make it suited to exposed building applications.
Where NovaFlex Makes Sense
Contractors may consider NovaFlex for:
- Metal roof seams
- Panel joints
- Joint filling
- Small gaps
- Details exposed to wide temperature swings
It remains flexible at temperatures down to -10°F and is freeze-thaw stable. There are a couple of limitations worth knowing before installation. NovaFlex is not recommended for joints that will be submerged underwater, and it should not be used on surfaces that will later be painted.
Cure time also depends on temperature and humidity, so installers should account for site conditions and follow the product instructions.
Contact GNMC about product availability.
Best for: Concealed metal building joints that need a continuous, flexible seal.
MB-10A Butyl Tape is an elastomeric butyl rubber sealant specifically designed around the requirements of metal buildings.
It comes extruded on silicone-coated release paper, which makes it straightforward to position during installation. It is also produced in different sizes and lengths to suit a range of applications.
Why It Works Well With Metal Roofing
MB-10A is designed to maintain its seal through normal building movement. Its combination of adhesive strength and cohesive strength helps the tape stay together and stay bonded as the assembly moves.
Temperature performance is another important benefit. MB-10A is designed to withstand extreme roof temperatures while maintaining compressibility in colder conditions. It also offers resistance to UV light and cold flow.
Those characteristics matter on metal buildings, where the material may experience a wide range of temperatures throughout the year.
Common Applications
MB-10A may be a good fit for:
- Concealed panel laps
- Metal building joints
- Overlapping components
- Details requiring a continuous butyl seal
- Joints affected by normal building movement
Choosing the right tape size is important. The joint needs enough material to create the intended seal without using so much that the tape squeezes excessively out of the detail.
Inquire about MB-10A Butyl Tape
What to Consider Before Choosing a Metal Roof Sealant
Before grabbing a tube or roll, look at what the joint actually needs and ask yourself the following questions:
- How Much Will the Joint Move? Metal panels expand and contract as temperatures change. A sealing product at a moving joint needs enough flexibility to accommodate that movement.
- What Temperatures Will the Product See? Metal roof surfaces can get hot, and Montana projects can also see very cold conditions. Check the product’s application temperature separately from its service temperature. A sealant may perform across a wide temperature range once cured while still having specific limits for installation.
- Is the Joint Exposed or Concealed? A concealed panel lap has different needs than an exposed seam. Butyl tape is often a practical choice where two materials are compressed together. A gun-grade sealant may make more sense when a seam or gap needs to be filled from the outside.
- What Materials Is the Product Touching? Always check compatibility with the metal substrate and any adjoining materials. A product that adheres well to bare metal may have different requirements around painted finishes, other coatings, plastics, or masonry.
- Will the Surface Be Painted? Some sealants are not paintable. Both TFC BUTYL and NovaFlex have limitations that should be understood before choosing them for a detail that will receive a finish later.
- What Does Installation Require? Good products still need good installation. Surface preparation, storage, bead size, compression, and cure time can all affect the finished seal. Read the product instructions before installation instead of assuming every sealant or tape works the same way.
Frequently Asked Questions About Metal Roof Sealants and Butyl Tape
What is the best sealant for a metal roof?
The best metal roof sealant depends on where it will be used. Gun-grade sealants can work well for seams and joints, while butyl tape is commonly used between overlapping components or in concealed joints. Movement, temperature, substrate compatibility, and exposure should all factor into the decision.
Is butyl tape good for metal roofing?
Yes. Butyl tape is well suited to many metal roofing details because it creates a continuous seal between components while remaining flexible enough to accommodate normal building movement.
Is sealant or butyl tape better for a metal roof?
Neither option is better for every application. Butyl tape is often used inside laps and concealed joints, while gun-grade sealants are useful for filling seams, joints, and gaps. Some details may use both as part of the roofing system.
Does metal roof sealant need to stay flexible?
For joints that experience movement, flexibility is important. Metal panels expand and contract as temperatures change, so the sealing product needs to accommodate the expected movement without losing adhesion.
Can you use any silicone sealant on a metal roof?
No. Use a sealant that is compatible with the roofing material, coating, joint design, and expected temperatures. The product instructions and roofing-system requirements should guide the choice.
Need Metal Roof Sealant or Butyl Tape for Your Next Project?
Great Northern Metal Company carries EMSEAL AST, TFC BUTYL™, NovaFlex, and MB-10A Butyl Tape for a range of metal roofing and metal building applications.
Tell our team what detail you are working on and what you need the product to do. We can help you review the options GNMC carries and get the right product information before you place an order.
Inquire About Metal Roof Sealants
