Joel King with a word about handling equipment during the winter...

This time of year, we often find ourselves agonizing over the startups of our vehicles parked outside in the driveway due to the cold. They take time to defrost, and all of that mechanical equipment needs time to warm up before operating properly. However, parking your vehicle in a temperature controlled garage makes it easier to get the vehicle running properly.

Just as vehicles benefit from protection from the elements, we should always remember that roofing materials need protection from the elements to function and be applied properly.

All membrane rolls, adhesives and coatings should be stored, for at least overnight, in a heated area, at a minimum temperature of 55°F (12.6°C) [above 73°F (23°C) is optimum] prior to their application, when the ambient temperature and wind chill factor are below 45°F (7.1°C).

Storage of materials overnight on the rooftop is strongly discouraged as this can lead to problems with unrolling the material such as wrinkling or cracking. Adhesives and mastics become chilled and, as a result, are thicker in consistency and harder to apply and take longer to cure. When temperatures reach or go below freezing, handling of rolls while frozen can result in severe wrinkling and/or cracking. This is normally most prevalent in the last ten feet of the roll. It must be understood that even though the ambient temperature has risen above freezing, the materials themselves will still be at a temperature too low to permit safe handling.

It is also necessary to keep the substrate dry. There can be no ice, dew or moisture on the roof substrate, especially when direct adhesion to the substrate is to be accomplished. The substrate must be warm enough so that condensation doesn’t occur at the time of application of hot temperature materials.

Here are some tips to consider when handling or using roofing materials during cool weather:

• OVER 55 “LIMIT FOR THE DAY”, UNDER 55 “LIMIT AS YOU GO”: When the ambient temperature will be greater than 55°F (12.6°C) for the day, remove from the protected storage area only those materials that will be installed the same day. When the ambient temperature will not be greater than 55°F (12.6°C) for the day, remove from the protected storage only the materials that can be applied as you go.
• ROLL SHORT: Rolls should be cut into shorter lengths for easier handling and to reduce the potential for wrinkles to form in the finished roof.
• ALLOW TIME TO RELAX: Then, the rolls should be unrolled, with the back side up and allowed to relax and warm. Then rerolled just before installation will reduce the potential for wrinkles to form in the finished roof.
• WARM THE SUB: Remember that the substrate temperature affects adhesion. If the substrate is below 55°F (12.6°C), then supplemental heating of the substrate may be necessary to avoid condensation or super cooling of asphalt or to avoid adhesion issues with torch, self adhesive or cold applied materials.
• SUNSHINE IS SAMS FRIEND: Self Adhering Membranes (SAMS) need warmer weather conditions and exposure to direct sunlight as essential requirements for proper adhesion. Application should be made when ambient temperatures are 50°F (10°C) and rising. Self-adhered membranes will not activate if installed in below recommended temperatures and/or if material temperature is below 70°F (21°C). Supplemental heat on substrate and underside of membrane is necessary to bond the self-adhered membranes in conditions where ambient or material temperature will not self activate the membrane.
• STICK TEMP IS OVER 70: Adhesives, coatings and mastics need to be kept inside until ready for use. On the jobsite, set pails in direct sunlight to help keep the material warm. It may be necessary to mechanically stir the product, if the material has thickened due to the cold weather. Remember viscosity ranges and application rates are based on a minimum material temperature of 73°F – 77°F (23°C -25°C). If material is applied when the product temperature is below 73°F (23°C), the product will be thicker and the material usage rate will increase because of the increased thickness of the product.

Here are some tips to consider when using roofing materials during temperatures below 45°F (7.1°C):

• MORNING START - OKAY TO HESITATE: Do not start mopping first thing in the morning. The surface over which the membrane is to be installed must be allowed to warm to a temperature above 55°F (12.6°C). It becomes critical to provide supplemental heat to the substrate in order to avoid condensation or super cooling of asphalt or to avoid adhesion issues with roofing materials.
• H20 IS A NO GO: When water in any form is present on the deck, application procedures must be suspended until the deck has dried. Any moisture present at the time the roofing is applied may result in poor adhesion and blistering of the membrane.
• IF HOT IS USED, INSULATE AND CIRCULATE: When hot asphalt materials are to be used, the correct asphalt EVT must be maintained. The use of an insulated, two-pipe circulating pumping system for asphalt is recommended for minimizing excessive application of asphalt in cold weather and for reducing use of heating fuel. Do not overheat the bitumen above the Flash Point or above the Finished Blowing Temperature for prolonged periods, to try to offset rapid chilling.
• MOP SHORT/ROLL SHORT: Mopped asphalt tends to congeal rapidly and lose its adhesive characteristics in cold weather, so extra care must be taken to set insulation or roofing quickly while the asphalt is still hot and fluid. Use minimum insulation board sizes. Keep the insulation or roofing roll close behind the mop. Mopping should not precede the material by more than two-three feet.
• BROOM IT AND MAKE CONTACT: Brooming glass felts is critical during cold weather and is mandatory to ensure full contact while asphalt is hot.
• CRACKING SEEN – STOP PLEASE: During installation, if surface cracking appears in the membrane, discontinue installation immediately.
• WATER BASED – PROTECT FROM FREEZE: All water-based adhesives and coatings must be protected from freezing at all times.
• COLD APPLIED TAKES LONGER TO DRY: In cooler weather, adhesives, coatings and mastics take longer to cure and are subject to be affected by the nighttime temperatures and next day’s weather – so consideration must be made for weather over a 24 hour span a time after a day’s work.
• DO NOT OVERHEAT TO COMPENSATE: Do not overheat asphalt or overheat rolls to compensate for cold ambient temperatures. Apply more heat on substrate to equally mate materials if applicable.
• DO NOT OPERATE IF TEMPERATURE TOO HARD TO BEAT: If the proper asphalt application or heat welding temperature cannot be consistently maintained, roofing must be discontinued. Be aware that cool, windy conditions will cause asphalt heat loss to occur at a rate equivalent to a lower ambient temperatures.