Friday / April 12, 2019 / 12:00 PM - 1:30 PM

Don’t Go With The Flow: Avoid PIB Migration

Bank of America Building, 135 South LaSalle Street, 43rd floor, Chicago

The migration of lightly colored polyisobutylene (PIB) primary sealant into the interpane space of in-service insulating glass units (IGUs) has been observed across the United States.  The sealant has moved within the exposed field of the IGU in excess of the dimensional limits recommended by insulating glass manufacturers and industry standards. The migration causes aesthetic and potential long-term durability concerns. Because the PIB cannot be repaired, the failure of this small component in IGUs requires IGU replacement to resolve and can be extremely expensive. We will discuss our experience with projects exhibiting PIB migration, contributing factors to the PIB migration phenomenon, and the measures designers can take to avoid this issue in their projects.

Speakers: Rebecca Booth is a licensed Architect in the State of Illinois. At Raths, Raths, & Johnson Inc.  (RRJ), Rebecca performs facade investigations involving condition survey documentation, repair design, construction administration, and litigation support.  Her project experience has involved the evaluation of a range of materials and systems including windows, curtain walls, roofing, sealants, stucco, and exterior insulation and finish systems (EIFS). She is a Certified Document Technologist (CDT) through Construction Specifications Institute (CSI) and is certified with the National Council of Architectural Registration Board.

Dennis Johnson is a Principal at RRJ who has over 40 years of experience in investigations, repair design, construction quality assurance programs, design peer review, and performance testing of exterior wall systems, fenestration systems, and glazing materials.  He has specialized in exterior wall system investigations, including window, curtain wall, and skylight systems with air infiltration, water leakage, material, and other performance related problems.  He is currently Vice President of the Insulating Glass Certification Council (IGCC).


  • Registration through BECC is mandatory. CLICK HERE TO REGISTER.
  • Do not arrive more than 10 minutes prior to the scheduled start time out of respect for Gensler.
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  • Bring your lunch.

Sponsored By

Building Enclosure Council-Chicago

Learning Units

1.5 LU/HSW

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