Double Lock Metal Roofing Systems Explained: Costs, Types, and Top Benefits

When investing in a metal roof, the double lock metal roofing system stands out as a top choice for homeowners seeking durability and a long lifespan. Compared to other metal roofing types, the double lock system offers superior weather resistance and structural integrity. In this article, we will discuss the costs, types, and benefits of the double lock metal roofing system, helping you make an informed decision for your roofing needs.

What Is a Mechanically Seamed/Double Lock Metal Roof?

Mechanically seamed metal roofs consist of panels with a concealed fastener standing seam system. Designed with clips that align, these panels are locked together using a mechanical or hand seamer, creating a highly weather-resistant barrier. This method reduces the likelihood of leaks and ensures a secure fit, making mechanically seamed roofs an excellent choice for various climates and architectural styles.

Single Lock vs. Double Lock Mechanically Seamed Systems

Single Lock System

  • Description: In a single lock system, the panel seams are folded once (90 degrees). This method is easier to install and is best suited for milder climates where extreme weather resistance is not a primary concern.
  • Advantages:
    • Faster and more affordable installation due to less labor.
    • Easier and quicker to repair if damage occurs.

Double Lock System

  • Description: The double lock system features seams folded twice (180 degrees), making it more labor-intensive and costly to install. However, it is more secure and weather-tight, offering superior performance.
  • Advantages:
    • Compatible with low slopes: Ideal for roofs with slopes less than 2:12, providing extra weather resistance.
    • More weather-tight fit: The twice-folded seams ensure no potential water entrance points.
    • Higher quality performance: Reduces the risk of seams coming undone, maintaining structural integrity.
    • Durability in freezing temperatures: Suitable for cold climates, preventing panels from coming undone due to expansion and contraction.

Benefits of the Double Lock Metal Roofing System

  1. Versatility in Design
    • Available in various widths (13” to 17”) and materials (24 gauge steel, .032 aluminum).
    • Multiple pan variations: smooth, striated, pencil rib, or flat rib to match your aesthetic preferences.
  2. Superior Weather Resistance
    • The double lock system’s secure seams provide exceptional weather-tightness, ideal for areas prone to heavy rainfall or snow.
  3. Durability and Longevity
    • Backed by a 35-year non-prorated finish warranty, ensuring long-term performance and peace of mind.
    • Resistant to expansion and contraction in freezing temperatures, preventing damage and leaks.
  4. Customizable Lengths
    • Maximum panel length of 35’ when factory or shop-formed, with virtually unlimited lengths when field-formed, accommodating any project size.
  5. Weathertightness Warranty
    • Additional weathertightness warranty available, ensuring your investment remains protected against leaks and weather damage.

Installation and Tools

The quality of a double lock metal roofing system’s performance heavily relies on proper installation. Both single and double lock systems require specialized tools, such as a mechanical seamer or hand seamer, for secure and precise panel seaming. Each clip must be hand-seamed before using a seaming machine, making the installation process meticulous but crucial for optimal performance.

Costs of Mechanically Seamed Metal Roofing

Mechanically seamed metal roof panels typically range from $3.00 to $6.00 per square foot. Additional costs include accessories, trim, and underlayment, which vary depending on the project’s specific requirements. While the initial cost may be higher, the long-term benefits and durability make the double lock system a worthwhile investment.

Choosing Between Single Lock and Double Lock Systems

The decision between a single lock and double lock system depends on your specific needs and climate conditions:

  • Single Lock System: Best for milder climates, faster and less costly installation.
  • Double Lock System: Ideal for cold climates, areas with heavy snowfall, and low-sloped roofs requiring extra weather-tightness.

Conclusion

The double lock metal roofing system offers unmatched durability, weather resistance, and aesthetic versatility. Whether you have a historic home or a modern architectural design, this system provides long-lasting performance and protection. For more information and personalized assistance, contact a 50 North Roofing representative to discover how the double lock metal roofing system can enhance your roofing project.