What is a key characteristic of roofing decks for low slope roofing systems?

The key characteristic of roofing decks for low slope roofing systems is that rigid board insulation can be securely attached to concrete roof decks using bitumen or liquid applied methods. This is crucial as it allows for effective insulation, which is essential in low slope systems to prevent heat loss and to manage moisture.

In low slope roofing, the deck often serves as the foundational layer where materials such as insulation, waterproofing membranes, and protective finishes are installed. Concrete decks are prevalent due to their durability and structural strength. Attaching insulation with techniques like bitumen or liquid-applied adhesives not only ensures the insulation remains in place but also enhances the overall thermal efficiency of the roofing assembly.

Other options do not appropriately characterize the essential elements of low slope roofing decks. For instance, while wood may be a material used, it is not the only option, and thus cannot be seen as a key characteristic. Similarly, requiring a layer of gravel is more pertinent to certain traditional systems, but not a defining feature for all low slope roofs. Lastly, having a mandatory slope of 2% for drainage is a guideline in roofing design rather than a characteristic of the roofing deck itself.