Bitumen Roofing Systems Compared
There are many ways to install a Modified Bitumen Roofing System. Below are the highlights of each Modified Bitumen installation method. You’ll notice that every different installation method has major unique differences, both during and after installation.
|Self Adhered||Cold Applied||Hot Applied||Torch Down|
|Speed of Installation||Fast||Slow||Slow||Fast|
|Safety during installation||Very Safe||Very Safe||Moderate||Extremely Unsafe|
|Fire Hazard||None||None||Moderate||Extremely High|
|Adhesion Technology||Adhesives preinstalled on sheet stick to previous layer||Liquid adhesives rolled out between layers.||Asphalt melted to 400 degrees, then spread between layers.||Torch flame applied to bottom of sheet, which melts it to previous ply|
|Method of Installation||1. Current Modified Bitumen sheet is laid over previously installed insulation or ply|
2. Backing paper is peeled off.
3. Modified Bitumen is laid back over previous layer and rolled in.
|1. Liquid adhesives are rolled over top of previously installed insulation or ply.|
2. Liquid adhesives are applied to back side of current ply.
3. Current ply is laid over previous layer and rolled in.
|1. Asphalt is melted in kettle, similar to a BUR Roof (Types of Roof Systems – BUR).|
2. Once asphalt becomes liquid, it is installed over previous layer (Insulation or previous ply)
3. Current ply is laid over previous ply
|1. Current Modified Bitumen sheet roll is placed at beginning of previously layer (Insulation or previous ply)|
2. As current roll is rolled out, torch flame is applied, melting plies together.
|Benefits||Clean, Safe, Quick, and high quality||Clean, Safe, and high quality||High quality||Quick, Inexpensive|
|Drawbacks||Expensive||Expensive||Most expensive, Can be unsafe, look messy||Low Quality, Very Dangerous, Major fire safety concerns, looks messy|
As an industrial or commercial roofing system, we no longer install torch down modified bitumen roofs due to the fire and safety issues. Installing torch down roofs requires extensive insurance premiums, if they will insure the project at all, due to the risks associated with this installation method. And, several competitors have actually burned down buildings with this product. For these reasons and more, we are recommending alternative modified installation methods.