For over 50 years, Butler Manufacturing has been at the forefront of metal roofing innovation, setting the standard with its MR-24 Roof System. Introduced in 1969, this standing seam roof system was the first of its kind and remains the industry leader due to its unmatched seaming technology.
Butler’s revolutionary Pittsburgh double-lock seam, combined with factory-punched precision and specialized seaming equipment, has created a roofing system that offers unmatched durability, weathertightness, and energy efficiency. Unlike traditional metal roofs that rely on fasteners and basic crimping, Butler’s technology forms a monolithic seal, reducing leaks and extending roof lifespan.
This article dives deep into why Butler’s seaming technology is superior, how it protects buildings from the elements, and the long-term advantages of choosing an MR-24 roof system.
The Origins of the MR-24 Roof System
The MR-24 Roof System was designed to address common failures in conventional metal roofing, such as leaks at seams, fastener failure, and thermal expansion stress. At the time, metal roofs were often held together with exposed fasteners, which were prone to loosening over time, leading to costly water damage.
Key Innovations from the Start:
✅ First standing seam roof system developed for low-rise buildings.
✅ First 360º double-lock seam, completed on-site for superior weathertightness.
✅ First system with factory-punched panels for precise alignment, reducing installation errors.
✅ First roof system tested for extreme wind uplift resistance, setting industry standards.
Since its introduction, more than 2 billion square feet of MR-24 roofing has been installed worldwide, proving its reliability in real-world conditions.
What Makes Butler’s Seaming Technology Unique?
- The Pittsburgh Double-Lock Seam
At the heart of the MR-24 Roof System is its 360º Pittsburgh double-lock seam, which provides:
🔹 A true monolithic weathertight seal – Unlike other roofing systems that use crimped or snapped seams, Butler’s seam is mechanically locked under 3,800 pounds of pressure, ensuring a perfectly uniform, leak-proof joint.
🔹 Zero exposed fasteners – Conventional roofs with fasteners through panels eventually develop leaks. MR-24 eliminates this risk.
🔹 Proven performance in extreme conditions – Butler tested the MR-24 seam by submerging an 18×18-foot roof panel tank with 10 inches of water for five months. The result? No leaks. It later passed stringent Miami-Dade hurricane testing.
- Factory-Punched Precision for Seam Integrity
One major reason for leaks in metal roofs is improper alignment of panels during installation. MR-24 eliminates human error by:
✅ Factory-punching all structural components, ensuring each panel aligns perfectly.
✅ Reducing installation time – No need for field modifications or adjustments, minimizing labor costs.
✅ Enhancing seam strength – Misaligned panels create weak spots. MR-24® panels always interlock as designed.
- The Roof Runner Seaming Machine – A Precision Tool
Butler’s proprietary Roof Runner Seaming Machine ensures uniform and consistent seams every time:
🔹 Mechanically forms the 360º seam on-site, completing the seam with precision.
🔹 Reduces installation time, eliminating the risk of uneven or weak seams.
🔹 Prevents errors – The machine ensures the seam is completed under the correct amount of pressure, something that can’t be guaranteed with manual crimping.
Performance Advantages of Butler’s Seam Technology
- Built to Expand and Contract with Temperature Changes
A major flaw in many metal roofs is that they don’t account for natural thermal movement, which causes:
❌ Fastener loosening
❌ Panel stress and cracking
❌ Seam failure leading to leaks
The MR-24 Roof System solves this problem with:
✅ Floating Roof Clips – Specially designed clips allow 2.5 inches of expansion and contraction, preventing seam stress.
✅ Staggered Panel Splices – Unlike standard roofs where seams line up (creating weak points), Butler staggers panel splices for extra durability.
- Unparalleled Weathertightness
The MR-24 seam is designed to be:
🌧 100% Leak-Free – The Pittsburgh double-lock seam prevents water infiltration.
🌪 Wind-Resistant – It meets UL Class 90 standards for extreme wind uplift resistance.
❄ Snow-Load Rated – Supported panel splices prevent midair buckling under heavy snow.
- Long-Term Cost Savings
Over a 50-year lifespan, the MR-24 roof system can save up to 90% on maintenance costs compared to conventional roofing.
🔹 Lower energy costs – Insulation options up to R-40 available.
🔹 Minimal repairs – No fasteners to tighten, no seams to reseal.
Installation Innovations for Seam Integrity
- Step-by-Step Precision Seaming
MR-24 panels are installed in a strict sequence, ensuring:
🔹 Alignment before seaming – No misaligned panels.
🔹 Immediate seaming after installation – Prevents moisture infiltration.
- Sky-Web Fall Protection System
To improve worker safety during seaming, Butler offers Sky-Web, a fall protection mesh that also:
✅ Supports insulation during installation.
✅ Prevents tool drops from damaging seams.
- Factory-Engineered Roof Curb Openings
A major leak point in metal roofs is where HVAC units and vents penetrate the system. Butler eliminates this risk with:
🔹 Weathertight roof curb designs – No exposed fasteners.
🔹 Fully engineered penetrations – Prevents leaks before they start.
Sustainability & Energy Efficiency Contributions
🌿 Made from recyclable steel – Reducing environmental impact.
☀ Cool Roof Technology – Highly reflective solar finishes reduce cooling costs.
🏆 LEED Certification Potential – Can help projects qualify for green building credits.
Wrapping Up
Butler’s MR-24 Roof System remains the gold standard in metal roofing. Its Pittsburgh double-lock seam, factory-punched precision, and floating clip system make it the most durable, leak-proof, and long-lasting metal roof available today.
If you’re considering a metal roof upgrade or a new construction project, reach out to us at MAR Building Solutions – Kansas CIty’s Butler Builder.
