What is the primary characteristic of single-ply membranes in roofing?

Single-ply membranes are defined by their construction, which consists of a single layer of flexible waterproofing material. This simplicity in design offers several practical advantages, such as ease of installation and maintenance. Single-ply systems are generally lightweight, which can reduce additional structural requirements for the building. They are available in different types, including EPDM, TPO, and PVC, each suited for specific environmental conditions and customer preferences.

The other options presented do not accurately describe the primary characteristic of single-ply membranes. While reflectiveness and energy efficiency can be features of certain types of single-ply membranes (such as TPO), this is not a defining characteristic of all single-ply materials. Additionally, describing single-ply membranes as heavy and durable or requiring multiple application layers does not align with their fundamental design, which emphasizes a single-layer approach for efficiency and simplicity.