Is the hot application of modified bitumen better than the cold application in roof repair?
Hot-asphalt method. Modified bitumen systems can be installed in conventional hot asphalt, allowing the use of common BUR equipment and application techniques. A roofing crew familiar with the BUR application will require limited additional training to become proficient in this application. Torch method. This application method is probably the second most common. When this application is to be used, a manufacturer typically increases the thickness of modified bitumen on the backside of the roll and adds a thin plastic burn-off film. The additional bitumen and burn-off film melt under the application of a propane-fired torch, and they adhere the membrane to the roof insulation or substrate. Torch application does not require the use of hot asphalt, eliminating the need for an asphalt kettle. In areas where asphalt fumes become an issue or where asphalt cannot be transported to a roof, the torch method might be a viable alternative. Cold-adhesive method. This third application option is
Hot-asphalt method. Modified bitumen systems can be installed in conventional hot asphalt, allowing the use of common BUR equipment and application techniques. A roofing crew familiar with the BUR application will require limited additional training to become proficient in this application. Torch method. This application method is probably the second most common. When this application is to be used, a manufacturer typically increases the thickness of modified bitumen on the backside of the roll and adds a thin plastic burn-off film. The additional bitumen and burn-off film melt under the application of a propane-fired torch, and they adhere the membrane to the roof insulation or substrate. Torch application does not require the use of hot asphalt, eliminating the need for an asphalt kettle. In areas where asphalt fumes become an issue or where asphalt cannot be transported to a roof, the torch method might be a viable alternative. Cold-adhesive method. This third application option is
Polymer-modified peel and stick membranes have to be soft enough to be installed in temperatures as low as 50 ºF. For this reason, they contain oils and tackifying resins that are not present in conventional modified bitumen membranes. In general, the performance requirements of peel and stick membranes are more stringent and they are more difficult to formulate than standard SBS products. The opposite is true of self-adhering underlayments. Because these sheets are nailed into the roof deck, they don’t have the rigorous high temperature requirements of a modified cap sheet or peel and stick membrane.
