Balancing Roof Drainage Needs and Energy Efficiency

Date: March 25, 2020 3:30pm
Location: The Conference Center at One North Wacker
sgh chicago

Wednesday, March 25, 2029

The Conference Center at One North Wacker
1 N. Upper Wacker Drive, 2nd Floor
Chicago, IL 60606

3:30 - 4:00 p.m. Registration & Refreshments
4:00 - 5:30 p.m. Presentation & Discussion
5:30 - 6:00 p.m. Networking Reception

We will also offer a morning session for this seminar.

Participants will earn 1.5 AIA CES Learning Unit (LU/HSW) for their attendance and the option to receive a certificate of completion for transfer to other continuing education credits.


Drainage is a critical aspect of low-slope roof design involving not only a building’s architecture, but also its structural, plumbing, HVAC, and insulation systems. A well-drained roof can last for decades, but a poorly draining one can cause maintenance nightmares that, in some cases, lead to structural instability. In addition, designers increasingly rely on tapered insulation to achieve roof drainage, but sometimes misinterpret the energy code requirements for these systems. In this presentation, we will provide recommendations for effective roof drainage design and identify how to avoid common pitfalls with careful coordination. We will also discuss innovative tools and approaches to help designers calculate the energy performance of tapered insulation and optimize its efficiency. Throughout the presentation, we will include project case studies to illustrate challenges and practical solutions.

After attending this seminar, participants will be able to:

  • Identify the options and key considerations when deciding how to drain a low-sloped roof.
  • Understand tapered insulation’s limited contribution to energy code compliance.
  • Recognize and avoid common pitfalls that inhibit proper drainage on some roofs.
  • Coordinate between the architect, plumbing engineer, and structural engineer to design roofs with effective drainage.


phil moser

Philip S. Moser, P.E. | Senior Project Manager
Philip Moser specializes in investigating and designing roofing systems, plaza waterproofing and paving systems, and below-grade waterproofing. His projects have also included analyzing building moisture and leakage problems, as well as evaluating and designing masonry facades, windows, and curtain wall systems. He contributes to ASTM International standards development in several committees, including D08 on Roofing and Waterproofing, where he serves as a subcommittee secretary and technical contact for various task groups. His research interests include quantifying the effects of moisture on physical properties of roofing materials. Philip is also a subject matter expert in tapered insulation design, TPO roofing, and wind uplift resistance of low-sloped roofing systems.

eric twomey

Eric J. Twomey, S.E., P.E. | Senior Consulting Engineer
As a member of Simpson Gumpertz & Heger’s Structural Engineering group, Eric Twomey has broad experience analyzing and designing new building structures, modeling for fabrication, and employing building materials in innovative applications. He is a leader in advancing SGH’s three-dimensional modeling capabilities in design for fabrication. Eric is an active member of the American Society of Civil Engineers, American Institute of Steel Construction, American Concrete Institute, and Chicago Building Congress.