What Is It Exactly?
When you break down the composition of modified bitumen, you find that it is asphalt, but with a twist. It has modifiers added to it that give it rubber or plastic-like properties. This makes the modified bitumen much more durable. There are a number of different combinations possible with these six basic layers:
- Insulation – This layer is there to keep the heat IN during the winter months and keep the heat OUT during the summer months. Not only does it help regulate temperature, but it also provides a stable base for the remainder of the layers.
- Base sheets – Either unmodified or modified plies or sheets used under the membrane.
- Modified bitumen membrane – This sheet of modified bitumen is reinforced with a composite carrier, fiberglass, or polyester.
- Adhesive – You need a bonding agent that will keep the layers together.
- Flashing – This protects against the perforations in the roof (heating units, A/C, vents) and the edges of the roof.
- Surfacing – This surface coat offers cooling roofing options and protects against weathering and UV rays.