Nightmares on the Edge: Lawsuits about Concrete Slab Tolerance and Deflection Related to Windows and Curtainwalls

2 modules


Course Length
1 hour

Self- Paced


This presentation initially took place at the 2020 Building Enclosure Symposium.

The author has been involved as an expert witness in multiple litigations where confusion, poor language, and competing demands have led to million-dollar lawsuits. The negative domino effect starts with specification language, may be affected by value engineering, continues through contract language, develops further in shop drawings, and culminates in a train wreck in the field. The train wreck later falls off a cliff when the slabs deflect over the long term in unanticipated ways. Often multiple parties share blame, including owners, architects, structural engineers, general contractors, façade manufacturers, and façade contractors. Presenting such a complex case to a judge or jury is challenging. After all, if the construction professionals can’t figure it out, how can non-construction judges and juries get it right? In this presentation, the author will focus on what went wrong in the construction process, and will offer solutions that can bring about positive shared expectations of all parties and ultimate project success.

Mark Meshulam, REWC

Façade Consultants | Northbrook, IL

Mark Meshulam has over 40 years of construction experience. Starting as a sales engineer, he eventually became an owner of one of the top commercial window companies in Chicago. He oversaw engineering, shop drawings, laboratory and field testing, and project management for hundreds of buildings. In the recent decade, he has offered clients the benefit of his experience as a consultant and expert witness. He works nationally and internationally—sometimes in high-profile legal cases, including crimes where glass is important evidence. His websites attract thousands of viewers who educate themselves by reading his 80 original articles.


By completing/passing this course, you will attain the certificate Certificate with IIBEC and AIA Logos

Learning Credits

Nightmares on the Edge: Lawsuits about Concrete Slab Tolerance and Deflection Related to Windows and Curtainwalls - Recording
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Added about 2 months ago, by L Allen
Added 5 months ago, by todd
Added 5 months ago, by Randy
Added 7 months ago, by William
Added 7 months ago, by Viesturs
Mark Meshulam was an excellent presenter, Very informative!
Added 9 months ago, by Trey
Added 9 months ago, by Anonymous
Added 10 months ago, by Robert
Added over 1 year ago, by Alex
Added over 2 years ago, by Soph
The tiered approach to failures in this presentation helps clarify and provide an avenue for keeping important elements in design for long-term value of a building.

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