As single-ply roofing systems have grown their share in the commercial roofing market, design considerations have been hotly debated. None more so than how the roof will be secured to the roof deck. This decision is likely to be influenced by code, roof deck construction, and budget. As a commercial property owner or manager tasked with roof asset management responsibilities, it is beneficial to know the basics. So, which is it? Mechanically attached or adhered?

Mechanically Attached

Mechanically attached roofing systems are the most commonly specified in the industry. They are generally selected when ease and speed of installation, and a tight budget, are meaningful design factors. They do, however, require a roof deck that can accept fasteners, such as those constructed of steel or wood. Above the roof deck, insulation in a thickness determined by design and code is attached to the deck with steel plates and fasteners, their attachment frequency defined by the manufacturer’s details and local wind uplift codes. Over the attached insulation, a roof membrane roll is laid out and screws and plates are again used, typically at the edge of the membrane roll, to attach the membrane through the insulation to the roof deck. The plates and fasteners are then covered by the next sheet as the rolls are successively put down. The overlapping sheets are then heat-weld together to create a monolithic and water-tight seal.


An adhered roof system, sometimes referred to incorrectly as “fully-adhered”, is attached with a specially formulated adhesive. This method is more time-consuming and expensive than a mechanically attached system and can also be more disruptive to building occupants that are sensitive to odor, as most of the adhesives used today flash off solvents and other VOCs as they cure. Recent adhesive innovations, particularly polyurethane foams, offer faster cure times with lower odors, at a premium price. Adhered systems have a considerably smaller market share than mechanically attached ones but are preferred by some specifiers and are frequently specified over concrete roof decks, as these decks are not practical options for mechanically attached systems. When designed and installed properly, an adhered roof system will provide exceptional wind uplift performance.

Which Should You Choose?

It’s crucial that you speak with a professional when making a roof membrane system securement decision. Innovative Roofing Group is committed to helping you make the best choice for your commercial building. Call 404-594-6038 or send us an email to get started today!