Modified bitumen roofing systems
Roofing with modified bitumen (mod-bit) offers a variety of technologies and installation methods. With proven historical performance and time-tested durability, mod-bit roofing products are a go-to material of choice for high-end low-slope buildings.
Understanding modified bitumen roofing
As parts of the asphaltic family of roofing solutions, SBS & APP Modified Bitumen and BUR are among the oldest and most common roofing technologies in use today, providing a reliable solution for both residential and commercial properties. Commercial asphalt roofing systems consist of two or more waterproofing layers, offering redundancy for durable waterproofing protection.
Explore mod bit productsField-proven for decades, GAF Mod-Bit roofing provides durability and performance
Weather resistance and durability
Thanks to high-quality raw materials and rigorous quality control, GAF SBS and APP Mod Bit and BUR roofing solutions provide durability and weather resistance for the long haul.
Solar-reflective options
Make GAF SBS and APP mod-bit membranes part of your cool-roof solution.
Hybrid solutions
Hybrid systems can increase the overall robustness of the assembly by combining characteristics of multiple roofing technologies, such as SBS Mod Bit and TPO.
Competitive limited guarantees
GAF No-Dollar-Limit commercial limited guarantees up to 35 years are available for qualifying systems.
Sample GAF mod bit and BUR roof system assemblies
SBS (styrène-butadiène-styrène)
SBS (Styrene Butadiene Styrene)-modified asphalt allows these membranes to achieve greater elongation ratings than other asphaltic systems. Can be hot-mopped, cold-applied, heat-welded, or self-adhered.
Browse SBS membranes
APP (polypropylène atactique)
APP (Atactic Polypropylene)-modified asphalt helps the roofing membrane to achieve durability and protection against the damaging effects of UV rays and weather elements. Typically torch-applied.
Toit multicouche
BUR involves melting bricks of asphalt and applying it between base, ply, and cap sheets with mops (hot mopping). Some jobs are finished with a layer of gravel overburden over the last layer of asphalt.
Browse BUR membranes
Comparatif de produits pour système de toiture SBS, APP et multicouche
Le SBS et l'APP sont des polymères pourvus de caractéristiques uniques, et les membranes fabriquées à partir de ces polymères sont classées par numéros ASTM, par types et par catégories. Le toit multicouche est un mode d’assemblage dans lequel plusieurs couches de feutre sont posées avec de l’asphalte chaud entre chaque couche.
Installation methods for mod bit roofing systems
Appliqué à chaud
Blocks of asphalt are melted in a large kettle and spread on the roof with mops .This is one of the oldest asphalt roofing techniques, and still provides a durable, water-resistant seal today.
Thermosoudé/appliqué au chalumeau
The installer melts the underside of the asphalt membrane using a torch. This allows the sheet to adhere to the substrate below.
Appliqué à froid
The installer attaches the roofing membrane to the substrate or previously applied layer of roofing material with a liquid adhesive (e.g, Matrix 101) using a notched squeegee or applicator gun.
Auto-adhésives
Self-adhered asphaltic membranes include a factory-installed adhesive, protected by a film backing. The membrane is rolled out, and the film backing gets peeled away to expose the adhesive.
Project profiles: GAF asphaltic roofing systems
Get inspired for your next Mod Bit roofing system project with these real-life GAF asphaltic profiles.
Foire aux questions
The most common misconception about mod-bit roofing is that it can't be part of a cool roof system solution. Modern granule technology, such as GAF EnergyCap™ granules in Bright White and Ultra Bright White provide CRRC-rated reflectance to your asphlat roofing system.
Durable and long-lasting, GAF mod-bit and BUR roofing systems are eligible for No Dollar Limit guarantees up to 35 years for qualifying systems.See the Commercial Roof Warranty Comparison Guide for details.
Like any roof, regular inspections and maintenance (patching leaks, clearing debris) can help extend the functional life of your mod bit roof. GAF propose une scheduled maintenance checklist se composant d’outils et d’informations d’entretien importants pour vous aider à optimiser les performances de votre nouvelle toiture et à garantir sa solidité pendant de nombreuses années.
Choosing the right roofing system depends on many factors, including (but not limited to) budget, size, building use, climate, and potential sustainability goals.