What is 'MB' or Modified Bitumen?
Modified Bitumen also known as MB or Mod Bit
Modified Bitumen (MB) is made from asphalt and is known as the industry’s most durable roofing membrane as it is used across the United States. A trusted manufacturer of MB is GAF. Despite high installation costs, building owners can take advantage of its unique, self-healing properties, depending on the product.
If installed correctly and maintained, MB can last twenty years or more. With that being said, MB roofing is one of the most trustworthy types of roofing in the commercial roofing industry. MB is made from asphalt and a variety of rubber modifiers and solvents which makes it very durable and can even repair itself if there is a puncture in the membrane. MB comes in several different colors including, gray, black, brown, and white.
Pros of Modified Bitumen:
- Thicker compared to other types of membranes
- Durable against foot traffic
- Self-healing
Cons Of Modified Bitumen:
- Has seams/laps every three feet
- Requires extensive maintenance
- Damages easily from ponding water
- Performs poorly against grease
- Expensive to install
Best Uses For Modified Bitumen:
- Buildings with high foot traffic that do not have grease containment systems
- Buildings with a few penetrations on the roof (e.g. HVAC, RTU curbs, electrical conduits, gas lines)
Cost of Modified Bitumen: High
