If you look around at the various types of low-sloped roofs, you will find a wide variety of types depending upon the type of roof, its location, and various other factors. In Burlington, Mississauga, and Oakville, Modified Bitumen is a widely used product for roofs by many roofing contractors.

Modified Bitumen roofing systems are composed of five different components which the roofing contractor can assemble in various combinations. The layers are built-up during installation of the product. They consist of the following:

Insulation – Provides a stable surface to which the layers are built up on. It also provides an R-Value of insulation to prevent heat loss.

Modified Base Sheets – A modified or unmodified base sheet is used under a top ply of modified bitumen (Bitumen is an asphalt product)

Modified Bitumen Membranes – These membranes are factory manufactured products. They consist of a co-polymer modified bitumen, which has been reinforced with fiberglass, polyester, or a composite.

Adhesive – Used to adhere the layers to the sub-structure of the roof. They can be either cold-applied or hot-applied depending upon the type of membrane being used and the contractor’s preference.

Surface Material – Provides a layer of UV protection. This is often applied in the factory but can be applied on-site.

Flashing – Metal flashing is used to seal the perimeter of the roof, any equipment that is protruding from the roof, and any pipes or vents.

As you can see Modified Bitumen is a complex product requiring skilled installation. In Oakville and Burlington, there are many qualified contractors available that can assess your roof and advise you if this is the right roof for you. It is not the only choice available so let’s look at the pro’s and con’s of this material.

Modified Bitumen comes in two different systems. Which one to use is left up to the contractor and their preference and what type of roof they are working with. The two systems are:

SBS (Styrene Butadiene Styrene) – These are installed using hot asphalt or cold adhesives

APP (Atactic Polypropelene) – These are installed using a hot torch in almost every application

Pros of Modified Bitumen:

− Durable in extreme weather conditions which is ideal for the regions of Southern Ontario
− Easy to repair tears or holes in the system
− It comes in rolls, which ease the application and keep costs down
− Manufactured in a factory which means the quality control is good
− It expands and contracts with the movement of the building
− It resists UV light, which reduces cooling costs in the summer and prolongs the life of the roof

Cons of Modified Bitumen:

− It can be difficult to detect the source of a leak
− It is not the longest lasting roof. Depending on the quality of the installation and the environment 10 – 15 years of service is common
− When using a hot-applied Modified Bitumen, safety is often a concern. Kettles of asphalt are dangerous and care must be taken when applying this product to schools
− Neighbors often complain of the smell of a hot-applied Modified Bitumen

If you are looking for an inexpensive low-sloped roof option, modified bitumen is a wise choice in the areas of Oakville, Burlington, and surrounding areas due to its weather resistance and elasticity. The best option for you would be to have a roofing specialist inspect your roof and advise you of the best option for your particular structure.