Adapting for the Cold
The Effects of Winter Weather on Roofing
by Gary Zimmerman, Territory Sales Manager, Roofmaster Products Company
(Editor’s Note: Gary Zimmerman has been with Roofmaster® for more than 25 years, and previously he was the Territory Sales Manager for Northern Los Angeles, California. He is a former roofing contractor, Pasadena Fire Captain, and United States Marine, and has extensive experience and knowledge in all aspects of roofing and solving unique contractor issues.)
Winter weather poses significant challenges for roofing projects, impacting materials, application techniques, and overall project success. Cold temperatures, snow, ice, and wind can compromise the performance of roofing materials and the quality of installation if proper precautions are not taken. Understanding these effects and adapting methods accordingly is critical for roofers working in harsh winter conditions.
Temperature Effects on Roofing Materials
Cold temperatures alter the physical properties of roofing materials, particularly liquid-applied membranes, sealants, and adhesives. Most roofing materials, such as asphalt-based coatings or polyurethane foams, rely on specific viscosity levels for proper application. In cold weather, these materials thicken, making them difficult to pump or spray. For instance, asphalt emulsions and sealants may become too viscous below 40°F, clogging equipment or resulting in uneven application. To counter this, contractors often heat materials to maintain optimal viscosity. Using heated storage units or inline heaters ensures that materials remain workable, allowing for consistent pumping and spraying even in freezing conditions. However, care must be taken to avoid overheating, which can degrade material performance or create safety hazards.
Impact on Single-Ply Membrane Welding
Single-ply roofing membranes, such as TPO or PVC, require heat welding to create strong, watertight seams. Cold weather complicates this process by slowing the molecular bonding of the materials. At lower temperatures, the membranes become less pliable, and the welding equipment may struggle to achieve the necessary heat for a proper bond. Roofers must weld more slowly to ensure adequate heat penetration, as rushing the process can lead to weak seams that fail under stress.
To address this, contractors often use test welds, especially when employing robotic welders. Test welds involve creating sample seams under the same environmental conditions and testing them for strength and integrity. This practice ensures that the welder settings are optimized for the cold, preventing costly repairs due to seam failures.
Additional Considerations
Beyond material challenges, winter weather introduces risks like ice buildup and slippery surfaces, which demand enhanced safety protocols. Snow and ice must be cleared from the roof before work begins to ensure proper adhesion and prevent trapped moisture. Additionally, shorter daylight hours and unpredictable weather patterns require careful scheduling to maximize productivity.
By heating materials to maintain viscosity, welding slowly, and utilizing test welds with robotic equipment, roofers can mitigate the effects of winter weather. These adaptations ensure durable, high-quality roofs despite the challenges of cold temperatures.
