Modified bitumen roofs are seen as the modern alternative to BUR roofs. While a BUR roof is installed by rolling down a membrane and then covering with bitumen (think of it as an asphalt-like substance), a modified bitumen roof combines the membrane and the bitumen into a single roll, which is often covered with colored granules. Depending upon which type of modified system is used, this type of roof can either be applied with heat or cold adhesive. Once the material is laid down, the seams are fused together to create a seamless roof covering. A modified bitumen roof has all the advantages of a BUR roof, but allows for the roofing contractor to install the roof without worrying about VOCs and other fumes. For that reason, modified bitumen is a great option when re-roofing a building that will have occupants during the installation process.
- Double layer provides added durability against weather, debris and foot traffic puntures
- No VOCs given off during installation
- Seams are heat-welded to ensure no gaps for moisture
- Lower labor costs than BUR
- Higher material cost
- Installation requires highly skilled and experienced roofing contractors to ensure proper installation