{"id":149,"date":"2023-06-22T10:30:30","date_gmt":"2023-06-22T15:30:30","guid":{"rendered":"https:\/\/www.iko.com\/comm\/?p=149"},"modified":"2024-04-15T20:52:41","modified_gmt":"2024-04-16T01:52:41","slug":"controlling-roofing-kettle-temperature-hot-asphalt","status":"publish","type":"post","link":"https:\/\/www.iko.com\/comm\/blog\/controlling-roofing-kettle-temperature-hot-asphalt\/","title":{"rendered":"Controlling Kettle and Maintaining the Temperature of Hot Asphalt in Cold Weather Commercial Roof Applications"},"content":{"rendered":"

The quality of a roof depends on proper installation techniques. In order to properly install\u00a0built\u2010up roofing systems (BURs)<\/a>\u00a0and other asphalt roof systems with hot mopping, you must heat the asphalt to the correct temperature in the kettle and apply it to the roof at its application temperature. However, this is more challenging in the winter. Cold air can rob the asphalt of its heat between the roofing kettle and the roof\u2019s surface. At low temperatures of -7 degrees C to 4 degrees C (20-39 degrees F), asphalt temperature may drop 20 degrees C (50 degrees F) in a matter of seconds.<\/p>\n

If the asphalt is applied below the ideal temperature, it may be too thick to apply evenly or seal properly to the\u00a0base sheet<\/a>\u00a0\u00a0or to itself. In order to compensate for this problem when hot mopping in the winter, many roofing professionals choose to heat their hot tar roofing kettle above the appropriate temperature. While this strategy works at first, the longer the installation job, the more the high temperatures take a toll on the asphalt, actually reducing its quality and ability to seal properly.<\/p>\n

There are other disadvantages and risks to overheating asphalt that you should know about. Plus, there are techniques you can use instead of overheating the kettle that may also increase your efficiency as well as the quality of your roof. Read on to discover those techniques.<\/p>\n

\n
\n\"Hot\n<\/div>\n
\n\"BUR<\/div>\n<\/div>\n

Asphalt Installation Temperatures<\/h2>\n

The proper temperature to heat asphalt before hot mopping is referred to as the equiviscous temperature (EVT). At this temperature, the asphalt is viscous enough to be mopped out evenly, but not too thin that it runs uncontrollably. This viscosity is measured in centipoise (cP). The ideal viscosity for hand mopping is 125 cP. For mechanical mopping, a lower viscosity, of 25 cP,\u00a0 is required. Manufacturers produce different asphalt products that may be thicker or thinner than average. Therefore, each product may have a different EVT. Manufacturers should inform you of that EVT, so that you can get the best results from their product.<\/p>\n

However, as a general principle, the Canadian Roofing Contractors Association\u2019s (CRCA) National Technical Committee suggests that SBS modified bitumen should be heated to 200 degrees C (400 degrees F), or the EVT as listed by the manufacturer, whichever is higher.<\/p>\n

You can also determine the proper temperature for asphalt application by following the\u00a0ASTM D312 guidelines<\/a>. Determine your material\u2019s ASTM type (the manufacturer may list it) and use the following chart as a guide:<\/p>\n

There\u2019s also a maximum roofing kettle temperature that you should not exceed. The ASTM D312 dictates that kettle temperature should be below 288 degrees C (550 degrees F). Ideally, you would keep your roofing kettle as low as possible within the EVT range, never approaching this temperature.<\/p>\n

\n\n\n\n\n\n
Asphalt by ASTM Type<\/th>\nRoofing Kettle Temperature<\/th>\nApplication Temperature in BUR Systems<\/th>\nFlash Point<\/th>\n<\/tr>\n
II IKO\u2019s\u00a0Asphalt Type Two<\/a><\/td>\n232\u00b0C (450\u00b0F)<\/td>\n231\u00b0C \u2013 255\u00b0C (448\u00b0F \u2013 491\u00b0F)<\/td>\n286\u00b0C (547\u00b0F)<\/td>\n<\/tr>\n
III IKO\u2019s\u00a0Asphalt Type Three<\/a><\/td>\n260\u00b0C (500\u00b0F)<\/td>\n232\u00b0C \u2013 256\u00b0C (451\u00b0F \u2013 493\u00b0F)<\/td>\n282\u00b0C (540\u00b0F)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

\"Bucket<\/p>\n

Problems of Overheating<\/h2>\n

What are the dangers and disadvantages of exceeding the EVT range or even the maximum kettle temperature?<\/p>\n