AEC Buildtech

Roofing TRACK 2: Roofing

Jim Kirby

Jim Kirby

Building & Roofing Science Architect

James R. Kirby, AIA, is a GAF building and roofing science architect. Jim has a Masters of Architectural Structures and is a licensed architect. He has nearly 25 years of experience in the roofing industry covering low-slope, steep-slope, metal, spray polyurethane foam, vegetative, and rooftop photovoltaics. He understands the effects of heat, air, and moisture on a roof system. Jim presents building and roofing science information to architects, consultants and building owners, and writes articles and blogs for building owners and facility managers, and the roofing industry. Kirby is a member of AIA, ASTM, ICC, MRCA, NRCA, RCI, and USGBC.

Roof System Design Can Help Optimize the Energy Efficiency of Low-Slope Roofs

Low-slope roofing assemblies include a wide range of configurations and installation options, from the individual component to the overall roof system. While a roof’s most basic function is that of keeping rain out of a building, its role in improving a building envelope’s energy efficiency has steadily increased in importance. Thermal insulation within a roof assembly has been standard for many decades and more recently membrane reflectivity has been a focus. However, additionally, the use of air barriers, the attachment method for the insulation layers, and securement choice for the roofing membrane within a roofing system design all have overall energy efficiency performance effects on a roof system. This presentation will discuss the benefits of fully adhered systems versus mechanical attachment, air barriers, and also provide a building science-based analysis of value engineering’s long term effects.


  1. Understand how the use of vapor retarders and air barriers affects roof system performance
  2. Learn why the roofing industry recommends the use of at least two layers of insulation
  3. Recognize the differences in thermal efficiency of the roof system based on securement types—from full-thickness screws and plates to a combination of fastened and adhered layers.
  4. Recognize that value engineering a roof system’s insulation can reduce initial costs but could cost significantly more in long-term energy cost increases.

AEC Buildtech Roofing Speakers
AEC Buildtech Agenda