Architects and Metal Roofs: 5 Steps to Speccing Right the First Time
When you’re specifying materials for a metal roofing or siding project, details matter. While it’s tempting to drop in specs from a previous project, what works for one building may not translate well to another, especially with metal roofing projects. At Great Northern Metal Company (GNMC), we’ve seen how one overlooked detail can lead to long lead times, material swaps, or installation issues on the jobsite.
But here’s the good news: speccing metal can be simple and efficient with the right process and the right support. Whether you’re working on a custom build in Bozeman or a commercial project in Billings, this guide will help you avoid the most common pitfalls and set your project up for success.
Architects and Metal Roofs: 5 Steps to Perfect Specifications
1. Get Specific, Not Generic
Metal roofing and siding systems aren’t one-size-fits-all. Panel types, thicknesses (gauges), colors, coatings, and installation methods vary widely—and so do the performance expectations for each project.
Copying specs from a previous project without tailoring them to your current one can cause mismatches. We’ve seen architects unknowingly specify unavailable gauges or outdated finishes that are no longer produced. The result? Project delays, change orders, and rework that could have been avoided.
Better approach: Start with specs written for this project. GNMC offers 3-part specs for every panel profile, developed in partnership with Sheffield Metals. They include everything you need—general requirements, fire and impact ratings, product data, installation guidelines, and finish options. If you’re unsure which profile or gauge is best for your build, just ask.
2. Know What’s Available Now
The metal industry changes. Lead times shift. Materials go in and out of production. If you’re working off old product sheets or assuming a supplier still stocks a certain finish, you might be designing a project around a spec that’s not actually orderable.
Pro tip: Before you finalize your spec, check in with the supplier. At GNMC, we can tell you exactly what’s in stock, what’s made-to-order, and what finishes or panel profiles are best suited for your timeline and climate. A quick five-minute call or email can save hours of redesign later.
3. Understand Performance Expectations
Montana’s climate throws a lot at buildings—snow loads, ice damming, high UV, wind, and freeze-thaw cycles. That’s why it’s important to specify panels that match both the building’s needs and the realities of the jobsite.
For example, some profiles don’t perform well when installed below a certain slope or others are better suited to wall applications than roofing and vice versa.
By discussing your goals with GNMC early, we can recommend panel types and specs that match the demands of your site and meet performance standards from day one.
4. Be Open to Feedback
We’ve worked with dozens of architects across Montana. The best experiences happen when there’s collaboration early in the process. When architects consult us before finalizing their specs, the results are always smoother:
- Fewer RFIs
- Fewer change orders
- Faster delivery
- Better accuracy
- Stronger working relationships
No detail is too small to ask about. Placement of chimneys, integration of snow guards, how panels terminate at ridges—these are all things we’re happy to discuss. We’ll always tell you what’s worked well in similar builds.
5. Use the Tools We’ve Built for You
GNMC provides full 3-part specs for all of our panels, including most concealed fastener and exposed fastener systems. If you’re not already requesting or downloading these, they’re a huge time saver. Each spec includes:
- General conditions
- Products and materials
- Execution and installation guidelines
- Fire and impact ratings
- Warranty language
- Finish and color options
These specs are designed to drop right into your plan sets with minimal editing. Plus, if you need a custom variation for your build, we’ll help you draft one.
6. Consult First!
If there’s one takeaway from this guide, it’s this: a quick consultation upfront can prevent big issues down the road.
At Great Northern Metal Company, we make it easy. Whether you prefer a five-minute phone call or a quick email with your plans attached, our team is here to help you spec the right panel, avoid costly oversights, and hit your timeline. We’ll tell you what’s in stock, what’s working well in similar Montana builds, and what details to watch for. It’s fast, collaborative, and tailored to your needs. No wasted time, no sales pitch, just real support from people who know metal.
Let’s Make Your Next Project Even Smoother
At the end of the day, we’re here to help you deliver a high-performance, low-stress metal project that reflects your design vision and stands up to Montana’s demands. We’re happy to review your drawings, answer material questions, and offer real-world insight before your spec goes to bid.
Before you finalize your next metal roof or siding spec, reach out. We’ll help you pick the right panel, write the correct spec, and set your project up for success.
Let’s talk—give us a call or send your plans our way. We’d love to be part of your process.
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.
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.
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.
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
