Other Components

What Else Makes Up a Roofing System?


The three biggest components of a commercial roofing system are the roof deck, insulation, and membrane. But there are other parts to consider, too. These components include adhesives, sealants, primers, fasteners and plates, and metal edges. What will you need to complete your next job? GenFlex is your partner for getting the stuff you need—and making it all as easy as possible to use.

Learn more about the parts of a commercial roof and how GenFlex can support your business.



Adhesive is used to bond two surfaces together. In low-slope roofing applications, adhesive holds the EPDM, TPO, or PVC system together. 

Common roof adhesive uses:

  • Attach a base layer of insulation to the deck
  • Bond multiple layers of insulation to one another 
  • Bond a cover board layer onto the insulation
  • Attach a waterproof membrane to a cover board 

GenFlex Adhesives

GenFlex Quick Dual™ Adhesive: Quick Dual adheres insulation or fleeceback membranes over approved substrates. It comes in a portable, pressurized canister and is incredibly easy to set up, shut down, and clean up. No specialized equipment needed.

GenFlex ISO Bond Adhesive: ISO Bond is available in a 5-Gallon Bag-in-Box size and can be used to adhere approved GenFlex roofing insulations to acceptable substrates. 

GenFlex One Step Insulation Adhesive: One step low-VOC adhesive adheres roof insulation and cover boards to acceptable substrates. It can be used to adhere multiple layers of insulation and on almost any size project. It’s small size allows for easy maneuverability around the rooftop and can be used for low-temperature installations. It’s the perfect ISO adhesive for smaller projects! 

GenFlex Quick Jet Adhesive: Quick Jet spray adhesive is an excellent alternative to roll-on adhesives. It can be installed in ambient temperatures as low as  25 °F (-4 °C), it's low-VOC, and allows for faster installation and minimal flash off time. Each adhesive canister is resealable and can be taken to the next job!  


Fasteners & Screws

Fasteners insert directly into the membrane and insulation to secure them to the building's structural deck. A roof with fasteners is called a mechanically attached or mechanically fastened roofing system. Fasteners are commonly used to secure base sheets, insulation, membrane, and perimeter edge metal. 


GenFlex Fasteners & Screws 

GenFast #12: Order pre-assembled screws and plates or individual fasteners to attach roofing insulation to steel and wood roof decks.

GenFast #14: Order pre-assembled screws and plates or individual fasteners to attach roofing insulation to steel, wood, and lightweight concrete substrates.

GenFast #15: Order pre-assembled screws and plates to or individual washer head fasteners to attach roofing membrane to steel, OSB, and plywood, or washer head fasteners to attach 

GenFast #16: Use MAX Fasteners in any GenFlex system for attachment of roofing membrane to approved steel or wood decks.

GenFast CD10: A hammer-in, non-threaded fastener designed to secure insulation and membranes to structural concrete. 


The GenFlex family of fasteners and screws is always advancing, so check out the full line-up here.



Sealants are used to waterproof a roofing system and protect it from weather conditions. A roof sealant can extend the life of an existing roof and support sealing around difficult areas, like angled pipes. 

GenFlex Sealers

GenFlex One-Part Pourable Sealers and Liquid Flashing are available for black EPDM and TPO/FlexWhite roof systems. This liquid flashing requires no mixing, is self-terminating, and conforms to any shape. It's water-resistant in just 90 minutes.* The product is so easy to use it can help lower the risk of incorrect application and increase flashing detail efficiency. 



Primer helps prepare a roof surface and promotes adhesion between the substrate and coating or membrane and accessories. Primer is not a replacement for any layer of roofing. Instead, it's a way to maximize the performance and protection of a roof system. 


GenFlex Primers

FlexWhite™ Clear Primer: FlexWhite™ cleans and primes GenFlex FlexWhite EPDM or TPO membranes prior to application of FlexWhite Peel & Stick™ accessories.

GenPrime: Available in 1-gallon and 3-gallon pails, GenPrime cleans and primes black GenFlex EPDM membranes prior to application of Peel & Stick™ accessories. 

All Purpose LVOC Primer: Available in 1-gallon and 3-gallon pails, All Purpose LVOC Primer is a solvent based primer designed to clean and prime EPDM and TPO membranes to receive Peel & Stick™ tape products and accessories.

GenFlex Vapor Shield Solvent Based Primer: This solvent-based primer is best for priming and preparing exterior concrete, metal, wood, and gypsum surfaces to enhance the adhesion of a GenFlex Vapor Shield Membrane.

GenFlex Vapor Shield Water Based Primer: This water-based primer is used to prime and prepare exterior concrete, wood, plywood, and gypsum surfaces to enhance the adhesion of a GenFlex Vapor Shield Membrane.

Clear Primer LVOC: GenFlex Clear Primer LVOC is an adhesion promoter designed to clean and primer GenFlex TPO membrane prior to application of TPO Peel & Stick™ accessories.  It is formulated to meet V.O.C. requirements of 2.13 lb/gal (250g/L) maximum.

Clear Primer: GenFlex Clear Primer is an adhesion promoter designed to clean and primer GenFlex TPO membrane prior to application of TPO Peel & Stick™ accessories.


Metal Edges

Metal edge systems include fascia, coping, drip edges, and gravel stops. Metal edge products enhance a roof system's attractiveness and serve as a protective layer against water filtration and wind uplight. 


GenFlex Metal Edge Systems 

GenFlex works with two great partners, Metal-Era and Hickman Edge Systems, to offer easy-to-install products and quality online support. Metal edge products are available ready-to-ship or as custom-made pieces. 

Fascia profiles: The fascia is a transition trim covering the edge of the overlapping membrane and protecting the roof from moisture.

Coping profiles: The coping is a sheet metal that bends to cover the top of a roof's parapet wall for an extra layer of protection. 

Drip edges and gravel stops: A drip edge protects materials on a building's side from water runoff. A gravel stop is a perimeter metal edge used to finish a low slope membrane and prevent gravel from washing away. Together, these components help ensure proper water routing away from the building.  


Complete Your Roof with GenFlex

A GenFlex representative can help determine the right roof system and components for your building type and geographic area. They can also help ensure your roof assembly complies with all local building codes, insurance, and installation requirements. We make it easy! Call a GenFlex expert near you today and learn more about the parts of a commercial roof that GenFlex can supply to you. 


*Based on testing conducted by or conducted on behalf of Holcim and represents our analysis of the test results.