Modified bitumen is a roofing material that is used primarily on commercial properties. It provides a rubber-like coating and provides protection from the elements of weather due to its waterproof nature. Modified bitumen consists of asphalt on top of a mat of reinforcement material, which is made from either fiberglass or polyester. The reinforcement is rolled onto the roof, and the asphalt is applied with a mop.
While this type of roofing material may seem easy to apply, there's one thing about asphalt that makes applying it challenging: it's viscous. This means it is a liquid when it is hot and hardens when it cools, which makes cold weather applications challenging. Here are a few tips on storing, handling, and applying modified bitumen roofing.
An area will need to be prepared for the delivery of the materials. Due to the heavy weight of the asphalt steel drums, they will need to be stored on the ground. However, in most cases, the delivery service will lift the reinforcement materials directly onto the roof. This saves time and labor during the application process, but it needs to be carefully thought out first.
While it may make sense to store the materials directly on the roof, they are too heavy to place in one central location. Most roofing structures are not designed to carry a concentration of weight in only one portion of the roof. If it is necessary to store the materials on the roof, evenly space them out throughout the roofing structure as much as possible. An alternative is to store the materials on the ground and use heavy equipment to lift them onto the roof individually as they are needed during application.
Protect from cold & wet weather during storage
All materials need to be protected from cold weather. As was explained earlier, asphalt becomes hard at low temperatures, which is why it is applied when it is hot. Asphalt for this type of application comes in steel drums. Since the drums will likely be outside prior to and during the application, barrel heaters will need to be used. Barrel heaters are designed to heat steel drums to keep the contents in a liquid stage.
The reinforcement rolls lose their flexibility in low temperatures, which means they also need to be kept warm. The rolls can be heated with waterproof concrete heating blankets, because the rolls also need to be kept dry. They cannot be placed directly on the surface, especially if the surface is moist from a recent rainfall or snow event. When wet prior to application of the asphalt, reinforcement materials can lose their stability and flexibility. Therefore, place the reinforcement materials on wooden pallets.
Keep the materials heated during the application process
For this type of roofing application, the asphalt needs to be in liquid form. Lines are placed in the steel drums to pipe the asphalt to the roof and into a mop bucket. In addition to keeping the steel drums heated, the lines that carry the asphalt from the drums to the roof will need to be heated. The mop buckets located on the roof will need to be heated with a bucket heater.
Brushes are used to apply the asphalt to the reinforcement materials after they are rolled out. On cold days, the asphalt can cool quickly during the application process. Contractors need to work quickly and efficiently by placing the mop buckets as close as possible to the application area. The application area should be kept as small as possible on extremely cold days so reinforcement material is not subjected to the cold temperatures for an extensive time while waiting for the asphalt to be mopped on.