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Flat Roofing


The most common flat roof system that we install is the Modified Bitumen Roofing Systems - This type of roofing is an evolution of asphalt roofing. It is made from asphalt and a variety of modifiers and solvents. There are several ways of connecting pieces of this material. In a heat application process the seams are heated to melt the asphalt together and create a seal. There is also a cold-applied adhesive application process, and some self-adhesive forms of this system. This material is also referred to as APP or SBS.

Manufacturing Method Modifiers are added to standard roofing asphalt to replace plasticizers removed during the distillation process. Bitumen is reinforced with fiberglass or polyester fiber matting in order to increase durability and strength.


The two most common types are SBS and APP. The use of SBS (styrene-butadiene-styrene) increases the flexibility of the membrane and allows it to have stronger expansion and contraction capabilities. APP (attactic polypropylene) increases the aging ability of the roof system. SBS is often the more popular system as the synthetic rubber additive increases the products flexibility.


Application Method Modified bitumen roof systems can be installed with the common torch method, asphalts, or cold adhesives. A standard SBS modified bitumen roof system is a two-ply system applied in rolls that overlap the edge of the previous roll.



  • Very durable

  • Weather resistant

  • Easy to repair

  • Factory manufactured rolls are easier to install and ensure quality control

  • Flexible, expands and contracts


Colson Roofing Inc. specializes in hot application work and is a fully insured contractor for all types of roofing applications. We are also certified and fully trained by SOPREMA Canada, Canada’s largest waterproofing manufacturer, in advanced techniques/installation methods.

SOPREMA is an international manufacturer specializing in the production of innovative products for waterproofing, insulation, soundproofing and vegetated solutions for the roofing, building envelope and civil engineering sectors. Founded in 1908, SOPREMA now operates in over 90 countries.

Since beginning operations in Canada in 1978, SOPREMA has manufactured and installed millions of square meters of membranes. Each year, hundreds of building professionals choose SOPREMA for the quality of its products and the comprehensive service of its technical support team.

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