Modified Bitumen roofs are single-ply systems that are most often roll-applied to the roof surface. They are similar to asphalt roofs but they have additional polymers in their materials that provide added protection from the elements and help in increase the lifespan of the product. These are the least popular flat roofing system discussed, but are still pretty common and have a good reputation. Many times, Modified Bitumen roofs are installed by rolling out the roofing material after it has been heated with a blow torch. The heating process allows the material to adhere to the roof surface.


This material has high reflectivity ratings, meaning the surface of your roof stays cooler in the sun and the inside of your building stays cooler on hot summer days. It is typically a quick install and the system adheres very well to the roof surface because it is melted and bonded upon application.


The most obvious disadvantage of this system is the danger of installation. Working on a roof with several blowtorches aiming directly into the roofing surface is dangerous. Without proper training and practice, it is very easy for an installer to set the roof on fire and damage part or all of the roof. That is why many buildings have been burnt down during the installation process of this roof. While this is dangerous and still occurs today, new methods have been developed and measures have been taken to minimize this problem.

Another downside of this product is its lack of scuff resistance. When it is walked on, it usually shows signs of traffic and wears down. It is also prone to tearing so foot traffic should be minimized and all workers must be extremely cautious.


You may have already noticed, but there is some discrepancy in the size of the advantages and disadvantages section. This is a roofing system that has few advantages and many disadvantages. That alone may dissuade you from using it on your building. If you’re still interested, just be sure that you contact a professional and get the entire scoop on your situation before making a decision.