Track 3: DELIVERY – INTERVENING INTO HISTORIC PLACES / Volet 3 : Réalisation – Intervenir dans les lieux historiques

Defying Gravity - Conserving Historic Stained Glass Lay Lights and Domes; Maximizing Structural Integrity While Maintaining Original Design Aesthetic

Friday, October 13
8:30 AM - 10:00 AM

Many of our significant historical structures are glazed with stained, leaded or decorative glass lay lights and domes. They are often found in courthouses and important government buildings. The subject matter and the way the subject is depicted within the leaded panels speak volumes about the public mores and prevalent culture of the day. It is imperative that we preserve these great works of art for cultural, artistic and historical reasons. There can also be health and safety issues; thousands of people walk and work beneath these glass ceilings every day.

Glass is very strong in compression but relatively weak in tension. Lead cames, the primary structural element of leaded glass panels, are highly malleable but not highly ductile. Lead has a low modulus of elasticity (E= 2.0). When leaded glass panels are placed into near or complete horizontal installations, the forces of gravity apply tensional strain to the glass and the lead. The lead experiences plastic deformation; the window deflects, typically downward. As the lead came matrix deflects, the glass is placed in tension. Once the glass exceeds its tensile limits, it breaks; as glass breaks, it weakens the panel, resulting in more deflection and more glass breakage. The cycle continues.

This paper will discuss the myriad forces that act to deteriorate leaded glass lay lights and domes. It will address the best practices to document the failure(s); this information is critical to designing the most appropriate conservation approach to follow. The paper will discuss best practice in terms of materials and technology to employ to rectify the immediate problems, proactively modify the design where necessary to forestall failure in the future all while maintaining the original design aesthetic and intent.

Three projects will be reviewed: the circa 1860 monumental lay lights of the U.S. Capitol, Washington, DC; the 27 lay lights, each panel measuring 8' x 9', of the DAR National Headquarters in Washington, DC; and the 50' diameter dome of the Allen County Courthouse in Ft. Wayne Indiana.

Arthur J. Femenella is dedicated to the conservation of stained glass and historic wood and metal windows and has been doing so for 44 years. Art marries a strong science background to the art of glass. His firm strives to educate and assist the stewards of our great glass heritage to make informed decisions; this has resulted in numerous preservation awards for his firm for projects all over North America. He has written over 50 articles on glass conservation and is frequently asked to speak at both national and international venues. Art is a Professional Associate of AIC; a board member of APTI; founder of the American Glass Guild. He is an active member of various other preservation groups.

Learning Objectives:

Arthur J. Femenella

President
Femenella & Associates, Inc.

Arthur is dedicated to the conservation of stained glass and historic wood and metal windows for 44 years. Art marries a strong science background to the art of glass. His firm strives to educate and assist the stewards of our great glass heritage to make informed decisions; this has resulted in numerous preservation awards for his firm all over North America. He has written 50 articles on glass conservation and frequently lectures at both national and international venues. Art is a Professional Associate of AIC and board member of APTI. He is an active member of various other preservation groups.

Presentation(s):

Send Email for Arthur Femenella

James Maddigan

Senior Associate
Robertson Martin Architects, Inc.

Mr. Maddigan, is a Senior Associate, and Building Conservation Specialist with the firm Robertson Martin Architects, Ottawa, ON. His career in heritage conservation started in 1995 on graduation from Algonquin College with a diploma in Architectural Technology, specialization in building conservation. In 2002, he received a Masters in Conservation of the Built Environment, from the Université de Montréal. Through education, experience and training he has developed an expertise in heritage conservation, with emphasis on heritage materials, assemblies and finishes. Buildings and projects he has worked on include: Chateau de Ramezay, Library of Parliament; Rideau Hall (Residence of the Governor General); and House of Commons (Centre Block).

Presentation(s):

Send Email for James Maddigan


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Defying Gravity - Conserving Historic Stained Glass Lay Lights and Domes; Maximizing Structural Integrity While Maintaining Original Design Aesthetic



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