We Met At The Parapet And It Was Transition At First Sight

Track 1: Design Sessions

Wednesday, May 9, 14:00 – 15:00

Securing the building envelope begins with the recognition that the majority of moisture and air intrusions occur at transition points including roof to wall, wall to foundation and wall to disparate building materials.

This session will examine the role these transitions play in allowing air and moisture intrusion & extrusion and the potential for mold, indoor air quality and material problems that result when these transitions are not properly sealed. We’ll discuss what constitutes an effective air and moisture management system in the roof to wall transition addressing: precipitation and bulk water movement, air flow and diffusive vapor flow. We’ll examine vapor drive through foundation walls in below grade transitions which, due to damp soil and other underground moisture, can pose risks yearround to above ground interior spaces. We’ll discuss how to navigate the issues that arise from transitioning to different materials, such as gypsum sheathing to concrete wall. We’ll present the influence materials composition, compatibility of materials, materials performance, and maintaining the integrity of the design specification through construction plays as well as the influence of quality control and system testing. We’ll provide insight into the role the system’s water and air barriers play to create air and water barrier continuity at these critical transition points, including the roof to wall transition at parapets where freeze thaw may occur in cold climates. An examination of the common design errors will also help attendees identify and avoid them. Finally, we’ll discuss the important role consultants who specialize in roof to wall transitions can play in the design process.

Learning Objectives:

  1. Identify the role that roof to wall, wall to foundation, and wall to disparate material transitions play in achieving a tight building envelope and what contributes to failure.
  2. Discuss the stages in the design process where transitions should be considered and what should be detailed.
  3. Review the states of moisture, their movement and how it impacts the roof to wall, wall to foundation and wall to disparate materials including the impact of vapor drive on interior spaces.
  4. Describe the considerations in material performance with respect to installation techniques, air and water barriers and vapor permeability and the impact on transition points.
Level of content:
Construction & Testing

Christine Cronin, M. Arch

Senior Associate
Building Science Corporation

Christine Cronin works with developers, contractors, and architects to mitigate the risk of technical failures in new construction.  She is well-versed in both commercial and residential design, reviewing drawings and making recommendations that promote appropriate water control, air control, constructability, durability, and energy efficiency.  For clients with a portfolio of upcoming projects, she assists in developing design standards commensurate with their tolerance for risk.  During the construction phase, Ms. Cronin reviews work in progress and addresses conditions or changes in sequence or scope that were not anticipated during the design phase.

Ms. Cronin is a Senior Associate at Building Science Corporation and is Vice-Chair of ASHRAE Technical Committee 1.12, Moisture Management in Buildings.  She received her Bachelor of Arts from Princeton University and her Master of Architecture from NewSchool of Architecture + Design.