Metal Roof Expansion and Contraction: Engineering Solutions for Phoenix’s Daily Temperature Extremes

Phoenix’s Scorching Heat Meets Metal Roofing: How Expert Engineering Solutions Conquer Daily Temperature Extremes

Phoenix, Arizona presents one of the most challenging environments for metal roofing systems in the United States. With an average of 111 days annually reaching at least 100°F and highs topping 110°F an average of 21 days during the year, including a staggering 70 days at or above 110 degrees in 2024, the Valley of the Sun demands sophisticated engineering solutions to manage metal roof expansion and contraction.

Understanding Phoenix’s Extreme Temperature Fluctuations

Over the course of the year, Phoenix temperatures typically vary from 45°F to 107°F, creating massive thermal stress on roofing materials. However, the real challenge lies in the daily temperature swings and surface heating effects. On long summer days, roof surface temperatures can easily surpass 150 degrees, while the surface temperature of metal roofing materials can range from 25 degrees Fahrenheit cooler than ambient air temperatures in the winter and more than 100 degrees Fahrenheit warmer than ambient air temperature in direct summer sunlight.

What makes Phoenix particularly challenging is that unlike most desert locations which have drastic fluctuations between day and nighttime temperatures, the urban heat island effect limits Phoenix’s diurnal temperature variation. This means metal roofs experience sustained high temperatures for extended periods, creating unique expansion challenges.

The Science Behind Metal Roof Thermal Movement

When metal is subjected to a change in temperature, it responds by changing size, known as thermal expansion and contraction. An increase in temperature makes the member bigger and a decrease in temperature makes the member smaller. The magnitude of this movement depends on several factors:

  • Material Type: Steel has a coefficient of thermal expansion of 0.0000065 per °F, while aluminum expands at 0.0000128 per °F
  • Panel Length: A 100-foot long steel panel experiencing a 100°F temperature change will increase in length by 0.78 inches, while an aluminum panel of the same length will increase by 1.56 inches
  • Temperature Differential: Based on Phoenix conditions, a base metal could have a temperature change of over 200°F

Engineering Solutions for Phoenix’s Climate

Professional roofing contractors in the Phoenix area must implement specialized techniques to accommodate thermal movement. To mitigate these risks, specialized clips and floating fasteners are used that allow the panels to move without causing damage. Additionally, proper spacing and seam design ensure that thermal movement is evenly distributed across the roof.

Standing Seam Systems: The Phoenix Solution

Many standing seam panel systems can accommodate 150-foot runs or greater. Standing seam systems have a clip attachment mechanism that accommodates the thermal movement of the panel without damage. With a standing seam system the roof movement is allowed from eave to ridge. There are many proprietary designs but all standing seam roofs float above the supporting structure as a steel membrane via clips.

Critical Installation Considerations

Proper installation is paramount in Phoenix’s extreme climate. Temperature when installing matters! If you are installing in the coldest climate, then you must allow for expansion. If installing in the warmest, then you need to allow for contraction. Professional installers must also consider:

  • Fixed Point Strategy: For a low pitched roof, using fixed cleats in the center of the panel and expansion cleats toward the ridge and eave is good practice. For a medium pitched roof, you want to move the fixed cleats closer to the ridge while the expansion should fall with gravity and expand toward the eave
  • Panel Length Limitations: Expansion cleats should be incorporated into the roof designs that have panel lengths of 20ft or longer
  • Quality Fastening Systems: Using floating fasteners that can absorb movement without loosening is essential, especially in areas with extreme temperature swings

Professional Installation: The Roofing All Stars Advantage

For homeowners in the Phoenix area seeking expert metal roofing phoenix solutions, professional installation becomes critical. Roofing All Stars LLC is a market leader in roofing and building services, with a local history serving Phoenix, AZ and the surrounding areas. Roofing All Stars is a full-service residential roofing contractor serving Phoenix, Chandler, Gilbert and the surrounding areas.

The company’s commitment to “Honest, Reliable, Quality Service” ensures customers can expect the highest quality of workmanship and the highest level of expertise, regardless of the size of your project. They specialize in most roofing systems including but not limited to, single ply membranes, concrete and clay tile, metal and asphalt shingles.

Preventing Common Expansion-Related Problems

Without proper engineering solutions, Phoenix’s extreme temperatures can cause significant issues. If the metal roof wasn’t installed with the appropriate allowances for expansion and contraction, it can result in stress on the panels (seam separation), leading to buckling, warping, or loosening of fasteners.

Without these considerations, the roof may experience buckling, leaks, or fastener breakage, ultimately compromising its longevity and performance. Thermal expansion/contraction is responsible for most roof leaks.

The Long-Term Investment

While proper engineering solutions for thermal movement may require additional upfront investment, in the long run a properly designed weather tight roof will cost less than an improperly designed leaky low cost roof. By understanding and accounting for thermal expansion and contraction, homeowners and contractors can ensure a durable, long-lasting, and efficient standing seam metal roof.

Phoenix’s extreme climate demands respect and expertise. The commitment to perform at the highest level of professionalism, safety and workmanship necessary to assure quality outcomes that stand the test of time becomes essential when dealing with the unique challenges of metal roofing in the Valley of the Sun. Professional installation by experienced contractors who understand thermal movement principles ensures your metal roof will perform reliably through decades of Phoenix’s temperature extremes.