Cool Weather Application Precautions for TPO and PVC
Roofing work doesn’t stop in the winter, but if you are applying single-ply roofing systems in the cool weather, there are precautions you should take. By following proper procedures, cold weather applications can progress more efficiently and effectively, resulting in higher quality roof installations. Here are some helpful tips.
Always follow any cool weather application instructions for the product or system you are installing when the temperature is below 45°F (7.2°C), as special care may be required. Acceptable weather conditions are not only based on the actual ambient temperature, but also the total combination of nature’s elements (e.g., wind, humidity, snow, sleet, etc.). These installation recommendations should reduce the potential for:
- Membrane wrinkling
- Failures and blow-offs due to improper adhesion
- Poor/false welds
- Membrane blisters on adhered systems
Careful planning of work during cool weather can greatly improve the quality of the installation and can minimize problems.
- There must be no ice, dew, or water on the roof substrate
- Do not apply roofing materials during inclement or threatening weather
- The roof substrate must be clean and dry
- All membrane rolls, adhesives, and coatings must be stored at least overnight at a minimum temperature of 55°F (12.8°C) prior to their application. All water-based products must be protected from freezing temperatures at all times. Any water-based materials that have been frozen must be discarded.
- Lay out the roof area and place materials where they will be needed prior to starting your application
- Complete each roof section daily. Application should be scheduled so there are no partially completed portions of the roof left exposed.
Membrane rolls are to be removed from the heated storage only as they are being installed. Install membrane rolls immediately after removal from storage to avoid membrane cooling.
Field seaming during cooler temperatures is an even more critical time to perform test welds in the morning, after any extended break such as lunch, or after significant change in weather (air temperature, wind speed, cloud cover, etc.). Many factors will affect the settings, including overcast skies and lower temperatures. This will require a slower speed that will provide the additional heat energy to compensate for heat-draining conditions.
- The correct speed and temperature settings for automatic welders are determined by preparing test welds at various settings
- Hand-welding during colder temperatures also needs to be adjusted
- Perform daily quality control, including probing and checking seams at the end of the day
Adhesives, sealants, and primers will take longer to flash-off and dry in lower temperatures.
- Adhesives, sealants, and primers should be kept in a warmer environment until just prior to usage in order to minimize exposure to cooler temperatures
- Not waiting the appropriate time it takes for the adhesive to set up (tack) will most likely result in adhesion problems
- At low temperatures, non-solvent-based adhesives, coatings, sealants, and caulks can be difficult to apply properly and may not adhere or cure as they do in warmer temperatures. Temperatures above 40°F (4.4°C) and rising are best. Do not heat adhesive containers with torches or other high-temperature devices
- Do not attempt to thin these products
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