Metal Roofing
Metal roofing encompasses a diverse family of roofing systems made from steel, aluminum, copper, or zinc that offer exceptional durability, longevity, and performance for both residential and commercial applications. Available in various profiles from traditional standing seam to products that mimic other roofing materials, metal roofing combines aesthetic versatility with superior weather resistance.
Composition
Metal alloy with specific composition for construction applications
Properties
Weight
0.7-3.0 lbs/ft²
Varies significantly by material and profile. Aluminum is lightest (0.7-1.0 lbs/ft²), steel ranges from 1.0-3.0 lbs/ft² depending on gauge and profile, while copper and zinc typically fall between 1.0-1.5 lbs/ft².
Thickness
24-29 gauge (steel), 0.019"-0.040" (aluminum)
Steel thickness is typically expressed in gauge (24-26 gauge common for residential, 22-24 gauge for commercial). Aluminum thickness ranges from 0.019" to 0.040", with copper and zinc typically 0.018" to 0.027".
Fire Rating
Class A (ASTM E108)
Non-combustible material that won't contribute to flame spread. Typically achieves Class A fire rating when tested as part of a roof assembly.
Wind Resistance
120-180+ mph
Properly installed metal roofing systems can withstand extreme wind conditions, with many systems tested to withstand hurricane-force winds exceeding 140 mph.
Impact Resistance
Class 1-4 (UL 2218)
Many metal roofing products achieve Class 4 impact resistance (highest rating), though thinner materials may have lower ratings. Performance varies by material thickness and panel design.
Solar Reflectance Index (SRI)
25-115
Unpainted metal has moderate reflectance. Light-colored and specially coated 'cool roof' metal products can achieve very high SRI values (70+), significantly reducing heat absorption and cooling costs.
Applications
Residential Steep-Slope Roofing
Used on single-family homes and multi-family buildings with pitched roofs (3:12 slope or greater), available in standing seam, metal shingle, tile, and slate profiles to suit various architectural styles.
Commercial Low-Slope Roofing
Applied to office buildings, retail centers, warehouses, and institutional buildings, typically using structural standing seam systems designed for slopes as low as 1/2:12.
Agricultural Buildings
Common for barns, equipment storage, and other farm structures where durability, weather resistance, and low maintenance are priorities, often using exposed fastener panels for cost-effectiveness.
Architectural Feature Elements
Used for decorative roof elements such as domes, spires, mansards, and accent roofs, particularly with premium materials like copper and zinc that develop distinctive patinas.
Solar Integration
Standing seam metal roofs provide ideal platforms for photovoltaic system integration using clamp-based attachments that don't penetrate the roof surface.
Coastal and Severe Weather Regions
Preferred in hurricane-prone, high-wind, and coastal areas due to superior wind resistance, corrosion resistance (with proper material selection), and durability in extreme conditions.
Advantages
- Exceptional longevity (40-70+ years depending on material and environment)
- Superior weather resistance including wind, rain, snow, and UV exposure
- Low maintenance requirements with minimal upkeep over service life
- Excellent fire resistance as a non-combustible material
- Energy efficiency through reflectivity and emissivity (cool roof options)
- Lightweight nature reducing structural requirements
- Environmentally friendly with high recycled content and recyclability
- Available in numerous profiles, colors, and finishes
- Can be installed over existing roofing in some applications, reducing waste
Limitations
- Higher initial cost than asphalt shingles and some other conventional materials
- Potential for oil canning (waviness in flat panels) due to thermal expansion
- Installation requires specialized knowledge and techniques
- Can create noise during rain or hail if not properly installed with solid decking and underlayment
- Some materials (particularly steel) require proper coating systems to prevent corrosion
- Color matching can be challenging for repairs or additions due to weathering and batch variations
- May dent from severe impacts (especially aluminum and thinner gauges)
- Higher embodied energy than some alternatives, particularly for aluminum
- Limited installer base in some regions compared to conventional roofing
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.