Modified Bitumen (Mod-Bit)

Modified bitumen membranes are quite popular as far as commercial flat roofing is concerned. They are made of asphalt bitumen and infused with either SBS or APP copolymers. Regular asphalt bitumen is brittle at room temperatures, and even more so when it is cold. The copolymers are introduced to modify these physical properties.

Types of Modified Bitumen Roofing

The two main kinds of mod-bit are:

Atactic Polypropylene Products (APP)
This is a by-product obtained while manufacturing Polypropylene. The plastic copolymer enhances flexibility and elasticity. It has a surface coated with granules, which helps to resist wear and tear, thereby improving the aging ability of the roof. It does not require additional protection and is best suitable for roofs that get heavy traffic.
Styrene-Butadiene-Styrene (SBS)
This is derived from butadiene and styrene and is a favoured choice by many people. It is a rubber copolymer and provides the asphalt bitumen with greater elasticity and flexibility even at lower temperatures. It is quite durable and abrasion-resistant. Although available in a wide range of colours, white and black are the most preferred shades.

Common Application Methods of Mod-Bit Roofing

Mod-Bit has a variety of installation methods depending on the individual requirements, including the following:

Hot Asphalt – Asphalt is applied to the felt with the help of a machine, over which the modified membrane is laid.
Torch Method – An open flame torch is used to melt the bottom of a sheet while applying.
Cold Adhesives – It is a cold process in which specially formulated asphalt is used as an adhesive to hold the membrane.

Applications of Modified Bitumen

Mod-Bit can be used for the following types of roofs:

Conventional – Here, the roof membrane is placed on the top of the insulation.
Inverted – Also known as the upside-down system, insulation is applied on top of the weather or waterproof layer.

Benefits of Mod-Bit

Durability
It has a proven track record and can easily last up to twenty years or more.
Resistant
The polyester and fibreglass layers can handle extreme weather, making it resistant to damages.
Low Maintenance
It is easier to maintain and ensure its quality. It requires less downtime in case of repairs.
Flexibility
Due to its ability to expand and contract according to the changes in temperature, it does not lose its shape or create gaps in the seams or between the flashing and roofing.