When it comes to building with steel, your roofing system plays a critical role in protecting your structure, supporting long-term performance, and maintaining structural integrity. Whether you’re planning an industrial warehouse, a commercial space, or a residential-style project, the metal roofing system you choose will directly impact your building’s durability, appearance, and energy efficiency.
In this article on metal roofing systems for steel buildings, we’ll explore the most common types of metal roofing systems used in steel buildings, walk through an overview of metal roof installation, and help you decide which roofing system is right for your needs.
Common Types of Metal Roofing Systems for Steel Buildings
Steel buildings require roofing systems that are not only structurally compatible but also capable of withstanding diverse and harsh weather conditions. From high winds and heavy snow to extreme temperature fluctuations and hailstorms, your roof is the first line of defence against the elements.
That’s why Norsteel works exclusively with high-quality metal roofing systems engineered for strength, longevity, and ease of assembly. Unlike traditional materials such as asphalt shingles, which are prone to cracking, curling, or impact damage, our steel panels offer superior resistance to denting, puncturing, and corrosion—even in hail-prone regions.
PBR Panels (Purlin Bearing Rib)
PBR panels, also known as a screw-down roof or exposed fastener system, this panel type is secured directly to the purlins using visible screws with washers.
PBR panels feature a deep ribbed profile with an extra purlin-bearing leg, which helps improve panel overlap, structural stability, and weather resistance. Because they are simple to install and cost-effective, they’re ideal for both large-scale and small DIY projects.
Quicker, Easier, and Less Expensive to Construct
Made from durable 26-gauge steel and designed to provide 36 inches of coverage per panel, these panels are widely used in pre-engineered steel buildings, offering a reliable balance of strength, affordability, and ease of metal roofing installation.
PBR systems are compatible with various insulation methods, including single blanket and Energy Saver systems. However, because fasteners penetrate through the panel and insulation, extra care is needed during installation to avoid compressing the insulation at screw lines and to maintain optimal thermal performance.
Standing Seam Roofing
Standing seam metal roofs are a premium alternative to screw-down systems. Unlike PBR panels, standing seam panels use concealed fasteners, meaning the screws are hidden beneath raised seams that lock into place.
This concealed fastening system reduces the risk of leaks and fastener loosening over time, especially in areas with frequent freeze-thaw cycles or high winds. It also delivers a sleeker, more architectural look, making it a popular choice for high-end residential or commercial steel buildings.
Standing seam systems are typically installed using clips or brackets that attach to the purlins but elevate the panels slightly above the roof framing. This creates a natural cavity between the insulation layer and the underside of the roof panel, offering several advantages:
- Allows for thicker insulation layers, such as cavity fill or Energy Saver systems
- Reduces insulation compression, helping maintain the full R-value
- Improves airflow control and overall thermal performance
The floating panel design of standing seam roofs offers multiple performance advantages. It accommodates natural thermal expansion and contraction, reducing stress on the roof system and helping prevent fastener fatigue or panel distortion over time, especially in climates with wide temperature swings.
This same flexibility also makes standing seam roofing ideal for steel buildings that experience vibration, such as crane buildings or industrial facilities. The panels can better absorb movement without loosening fasteners or creating ripple effects across the roof, maintaining structural integrity and interior protection over the long term.
Standing seam roofing is ideal for clients seeking low maintenance, exceptional durability, modern aesthetics, and enhanced energy efficiency.
For a deeper dive into the environmental benefits, energy performance, and architectural appeal of this system, explore our blog on Standing Seam Roof Benefits on Pre-Engineered Metal Buildings.
Coatings & Colours
Norsteel roof panels are manufactured from AZ55 Galvalume® steel, a material known for its exceptional corrosion resistance and durability. The aluminum-zinc alloy coating offers superior protection compared to traditional galvanized steel, making it ideal for long-term roof performance in a range of climates.
To support this durability, our roof panels come with a 25-Year Limited Rust-Through Perforation Warranty—providing added confidence that your investment is built to last.
Coloured panel options are also available, allowing you to choose a finish that complements your building’s style or branding. These factory-applied finishes are backed by a 40-Year Limited Paint Warranty for lasting colour retention, along with a 30-Year Limited Chalking and Paint Colour Change Warranty to keep your roof looking fresh with minimal maintenance.
Metal Roof Designs for Steel Buildings
While panel type and coating matter, your building’s roof design also plays a role in selecting the right metal roofing system. Roof shape determines drainage, snow management, and aesthetic profile.
Here are some common roof designs used in steel buildings:
Gable (Double Slope)
The classic peaked roof with two symmetrical slopes. This is the most common roof design for steel buildings and allows for excellent water and snow drainage. It pairs well with both PBR and standing seam systems.
Single Slope
A roof that slopes in just one direction. Commonly used for warehouse rows, lean-tos, and storage units, this design directs runoff to one side of the building. It also simplifies metal roof installation in some applications.
Lean-To
A secondary roof structure that attaches to an existing building. It’s often used to add a sheltered workspace, carport, or additional storage area.
Saltbox Roof (Off-Set Peak)
An asymmetrical variation of a gable roof, where one slope is longer than the other. It offers a unique profile and can enhance airflow or headroom, depending on interior layout.
To learn more about roof designs and steel building concepts, visit our The Metal Building System: Designs, Measurements & Key Concepts blog.
How Roof Pitch and Building Width Affect Your Roofing System Choice
Once your roof shape has been defined—gable, single slope, or other—the next two factors to consider are pitch (slope) and building width. Together, these influence how water and snow are shed from the roof and what type of metal roofing system will perform best.
What Is Roof Pitch?
Roof pitch is a measure of how steep or shallow your roof is. It is expressed as a ratio between vertical rise and horizontal run, typically per 12 inches of run.
For example:
- A 2:12 pitch means the roof rises 2 inches for every 12 inches of run.
- A 4:12 pitch means 4 inches of rise per 12 inches of run.
- A 1:12 pitch is considered nearly flat.
Formula:
Rise ÷ Run = Slope
Example: A 2″ rise over 12″ run = 2 ÷ 12 = 0.167, or a 2:12 pitch
The lower the pitch, the slower water will drain—so your roof system must be designed accordingly.
Matching Roof Systems to Roof Pitch
Screw-Down Metal Roofs (e.g., PBR Panels)
- Minimum Pitch: 2:12
- Why: These systems use exposed fasteners, which require a decent slope for water to drain off quickly and avoid pooling around screw penetrations.
- Not recommended for lower pitches, as water can collect and increase the risk of leaks.
Standing Seam Roofs
- Minimum Pitch: As low as ¼:12 or ½:12, depending on the system and sealant use.
- Why: These panels have concealed fasteners and raised seams, making them more watertight and ideal for low-slope roofs with slow drainage.
Building Width Also Affects Drainage
Drainage depends not only on pitch, but also on the horizontal run of each roof slope—which is defined by the building’s width. A wider building has more run, which provides more room for gravity to move water, even on shallower slopes.
Narrow Building (24′ wide, gable roof)
- Each slope is 12′ of run.
- A 2:12 pitch gives a total 2′ rise per slope.
- This provides just enough drainage for screw-down panels.
- Standing seam may be preferred for extra leak protection if building use or climate calls for it.
Wide Building (100′ wide, gable roof)
- Each slope is 50′ of run.
- Even a 1:12 pitch provides over 4′ of rise per slope.
- In this case, the long run compensates for the low pitch, so screw-down systems can perform effectively.
Pro Tip
When planning your steel building:
- Consider pitch + width together to select the ideal roof system.
- Use standing seam on flatter or narrower roofs where drainage is more limited.
- Use screw-down systems when pitch is 2:12 or greater and the width supports sufficient runoff.
- Talk to your steel building provider to ensure your choice is engineered for long-term performance in your specific region.
Metal Roof Installation: What to Expect
Metal roofing systems are installed on top of a structural steel framework composed of columns, rafters, and purlins. These components are carefully engineered to support the weight of the roof while distributing snow, wind, and live loads safely to the foundation. Our engineering process ensures precise spacing and sizing of these members, allowing for seamless panel installation and long-term stability.
With the structure in place, the next step is installing the roof panels themselves. One of the most common questions we hear is: how to install metal roofing on a steel building? While the exact steps may vary based on your building system and panel type, here’s a general overview of the process.
1. Preparation
Before installing metal roofing, it’s important to ensure the frame is square, level, and properly braced. Your roof purlins should be correctly spaced, and any insulation should be installed first if applicable.
At Norsteel, all buildings are shipped with labelled panels and detailed drawings, so you can identify and place each component accurately during installation.
2. Aligning the Panels
Start at one end of the building and lay the first panel square to the eave and ridge. Proper alignment of the first panel is critical—it will dictate how straight the rest of the roof looks.
PBR panels are placed directly on the purlins and fastened with screws along the rib lines. Each subsequent panel overlaps the previous one at the purlin-bearing leg for a tight seal.
3. Fastening and Overlaps
Screw patterns, fastener types, and spacing are all specified in your drawings. Use sealing tape or butyl sealant between overlaps as required. Install closures under the panel ribs at the eaves and ridges to prevent water or insect infiltration.
4. Ridge Cap and Trim Installation
Once all panels are in place, install the ridge cap, gable trim, and any other accessories such as gutters or snow guards. For standing seam systems, this may include a clip system and snap-lock seams for weather-tight performance.
Screw-Down vs. Standing Seam: Key Installation Differences
The metal roofing installation process differs depending on the panel system you choose. Screw-down (PBR) systems are generally easier and faster to install, while standing seam systems require more precision and are often handled by experienced professionals.
Here’s a quick comparison to help you evaluate both options:
| Feature | Screw-Down (PBR Panels) | Standing Seam |
|---|---|---|
|
Fastener Type |
Exposed screws with washers |
Concealed clips or fasteners beneath raised seams |
|
Installation |
DIY-friendly and faster to install |
Requires specialized tools and more precision |
|
Maintenance |
May need periodic screw checks and re-tightening
|
Lower maintenance over time
|
|
Appearance |
Functional, industrial |
Sleek, modern, and architectural |
|
Cost |
More budget-friendly |
Higher upfront cost, but long-term value |
|
Ideal Use |
Agricultural, industrial, DIY builds |
High-end commercial or residential-style applications |
How to Choose the Right Metal Roofing System for Your Steel Building
Choosing the best roofing option depends on more than just the building’s size or use. Here are some key factors to consider:
1. Building Application
Industrial or Agricultural: PBR panels often provide the strength and simplicity needed for large open spaces.
Commercial or Residential: Standing seam offers visual appeal and long-term value for storefronts, offices, or living spaces.
2. Weather & Climate
Consider local snow load, wind exposure, and rainfall patterns. Norsteel’s engineering team ensures your roof is designed to meet all local code requirements.
3. Appearance & Finish
Do you need to match a brand colour or surrounding buildings? Norsteel offers customizable colour and finish options to suit your aesthetic goals.
4. Budget & Longevity
PBR panels are more cost-effective and quicker to install.
Standing seam is a longer-term investment with reduced maintenance needs.
5. Installation Method
If you’re installing the building yourself or with limited help, screw-down (PBR) systems are often more practical.
If you’re working with a general contractor or want a sleeker appearance, standing seam may be worth the upgrade.
Why Choose Norsteel for Your Metal Roofing System
We design and manufacture pre-engineered steel buildings across North America with roofing systems built to perform in all environments. When you order a Norsteel building, you receive:
- Pre-labelled panels with detailed layout drawings and all required fasteners, closures, and sealing components for roof installation
- Clear installation guidance, whether you’re assembling the building yourself or working with a contractor
- Responsive customer support throughout every stage of your project
- Durable, factory-applied coatings designed for long-term performance and weather resistance
- Optional accessories including insulation, gutters, ridge vents, and snow guards to complete your build
No matter where you’re located, Norsteel delivers quality, reliability, and support from start to finish.
Final Tips Before Installing Metal Roofing
- Always double-check measurements and alignment before fastening.
- Use only the recommended fasteners and sealants.
- Do not over-tighten screws—this can damage panels or gaskets.
- Refer to your building’s manual for detailed roof installation instructions.
Visit our Manuals Page to download digital copies.
Get Started With Norsteel
Choosing the right metal roofing system is a big step in your steel building project—and we’re here to help.
Ready to get started? Fill out our form for a free, no-obligation quote or contact us to speak with a Norsteel consultant about your roofing needs.
