Corrugated Metal Roofing
Corrugated metal roofing consists of thin metal sheets formed into a repeating wave or rib pattern, creating structural rigidity while maintaining lightweight characteristics. This exposed fastener system combines economy, durability, and ease of installation, making it one of the most widely used roofing materials globally for agricultural, industrial, commercial, and increasingly, residential applications.
Composition
Corrugated metal roofing is manufactured by roll-forming flat metal sheets into a repeating wave or rib pattern that provides structural strength and rigidity. The base metal is typically steel (24-29 gauge), though aluminum, copper, and zinc versions are also available for specific applications. Steel panels are protected from corrosion through various coatings, with galvanized (zinc coating), Galvalume (zinc-aluminum alloy coating), or painted finishes being most common. Standard corrugated profiles include traditional sinusoidal waves (2.5-2.67" pitch) and more contemporary ribbed or trapezoidal patterns (6-12" pitch) with varying heights (1/2"-1.5"). The panels are installed with exposed fasteners—typically self-drilling screws with neoprene washers or gaskets—that penetrate through the panel high points (ribs) into the structural supports below. Panel lengths range from stock sizes (typically 8'-16') to custom lengths up to 40' for certain applications. The system includes various trims, flashings, and accessories for ridge caps, eaves, valleys, and transitions. Installation typically requires a minimum slope of 3:12, though some profiles can accommodate slopes as low as 1:12 with appropriate sealants and installation techniques.
Properties
Weight
0.7-1.5 lbs/ft²
Weight varies by material and gauge. Standard 29-gauge steel panels typically weigh 0.7-0.9 lbs/ft², while heavier 24-gauge steel may reach 1.2-1.5 lbs/ft². Aluminum versions are approximately 40% lighter. This lightweight nature reduces structural requirements and simplifies installation, particularly for large spans and retrofits over existing roofing.
Panel Thickness
24-29 gauge (0.0179"-0.0336")
Steel panels are typically available in 29 gauge (0.0179") for economy applications, 26 gauge (0.0217") for standard applications, and 24 gauge (0.0336") for premium or high-wind applications. Thicker gauges provide enhanced durability, wind resistance, and walkability, though at increased cost and weight.
Corrosion Resistance
Varies by coating
Corrosion resistance depends primarily on the protective coating. Galvanized coatings (G60-G90) provide 20-30 years in normal environments, Galvalume (AZ50-AZ55) offers 30-40+ years, and premium paint systems (PVDF/Kynar 500) can extend performance to 40-50+ years. Coastal environments and industrial areas with chemical exposure significantly reduce expected service life without appropriate material selection.
Wind Uplift Resistance
60-150 mph
Wind resistance varies significantly based on gauge, profile, fastener pattern, and substrate. Properly installed systems with appropriate fastener density can withstand winds of 90-150 mph, though performance is highly dependent on installation quality and edge securement. Failure typically occurs at fastener points rather than panel rupture.
Fire Rating
Class A (with appropriate underlayment)
Metal panels are non-combustible and typically achieve Class A fire ratings when installed with appropriate underlayments. The material will not ignite, support combustion, or spread flame, making corrugated metal suitable for wildfire-prone regions and applications with stringent fire code requirements.
Solar Reflectance Index (SRI)
Dark: 25-35, Light: 50-70, Premium Cool: 75-90
Solar reflectance varies significantly by color and coating. Standard dark colors typically have SRI values of 25-35, while light colors range from 50-70. Premium cool roof coatings can achieve SRI values of 75-90, significantly reducing solar heat gain and cooling loads. Many corrugated metal systems qualify for ENERGY STAR and cool roof certifications with appropriate finishes.
Applications
Agricultural Buildings
Predominant roofing material for barns, equipment sheds, livestock facilities, and other farm structures due to economy, durability, and ease of installation. The material's lightweight nature allows for large spans with minimal structural support, while the corrosion resistance withstands agricultural environments.
Industrial and Commercial
Widely used for warehouses, manufacturing facilities, storage buildings, and retail structures where economy and performance are priorities. The system's low maintenance requirements and ability to span long distances with minimal supports make it particularly suitable for large commercial buildings.
Residential - Rural and Contemporary
Increasingly popular for rural homes, mountain cabins, and contemporary residential designs where the material's aesthetic aligns with architectural intent. Modern finishes and profiles have expanded residential applications beyond traditional rural contexts to include high-end contemporary homes.
Retrofit and Recover
Frequently applied over existing roofing as a recover system, eliminating tear-off costs and disruption while providing enhanced performance. The lightweight nature makes corrugated metal ideal for retrofit applications where structural capacity may be limited.
Economical Housing
Essential material for affordable housing, disaster relief structures, and developing regions where cost, performance, and ease of installation are critical factors. The material's global availability and simple installation techniques make it accessible in diverse economic contexts.
Utilitarian Structures
Standard solution for garages, workshops, carports, and utility buildings where functional performance takes precedence over premium aesthetics. The system's economy and durability make it ideal for secondary structures where budget considerations are paramount.
Advantages
- Economical initial cost compared to many roofing alternatives
- Lightweight nature reducing structural requirements
- Long service life with minimal maintenance
- Excellent fire resistance and non-combustibility
- Fast and straightforward installation
- Available in long lengths to minimize seams
- Highly recyclable at end of service life
- Good performance in high wind with proper fastening
- Wide range of colors and finishes available
Limitations
- Exposed fasteners creating potential leak points over time
- Susceptibility to oil canning (waviness in flat areas)
- Potential for noise during rain and hail events
- Limited insulation value without additional systems
- Condensation concerns in unventilated applications
- Susceptibility to damage from foot traffic
- Potential for corrosion at cut edges and scratches
- Less refined aesthetic compared to concealed fastener systems
- Fastener gasket degradation requiring maintenance
Sustainability Profile
Metals are highly recyclable with minimal loss of properties, contributing to circular economy principles. Energy-intensive production is offset by long lifespan and recyclability.