Glass Going Oversize- The Fabricator's View
Second of three stories on this design trend. A decade ago when an architect designed a structure with openings that were larger than the standard size parameters that the glass fabrication community was geared to fabricate, very few options were available. Less than a handful of suppliers in North America could produce oversize material, and if you did get it, the glass usually came “as is” with no warranty. Today this is not the case. Thanks to supply chain growth and maturity as well as technology improvements and advanced equipment, fabricators have a different attitude and approach to jumbo-sized glass products.
Posted by Dominique Hébert on 09/24/2018
Oversize products, according to the architects we interviewed in the first article of this series range from widths of 82” to 98” and heights from a 160” to 220”. These oversize dimensions can create significant challenges regardless of today’s advanced equipment and fabricator know-how.
“A huge challenge is safety. As the units get larger, we have to ensure the proper equipment is used; training and restrictions are required to guarantee the safety of our employees. The next hardest challenge is deciding how much to invest, and where in the process. Initial capital for equipment to handle the weight and size of the larger units is required. Investing in a technical team to review all units with regard to load, deflection requirements, edge pull-out, dead load and silicone sight lines is also needed. Of course, more training for both handling and visual QC inspection teams on these larger units is also required,” said Tim Kelley, President and Owner, Tristar Glass, a major glass fabricator with locations in Catoosa (Tulsa), Oklahoma City, Oklahoma, Grand Prairie (Dallas), and Houston (Texas).
The overall quality of glass does matters, and “as is” is no longer adequate. Higher standards are demanded from today’s discerning clients. One area of product quality called “anisotropy” is critical to the look and performance of glass, especially when it pertains to the oversized segment.
“As a manufacturer and supplier of monolithic, laminated and insulating glass panels to the high-end retail markets, we produce larger panels that must use heat-treated components, ionoplast interlayers and multi-layer assemblies. This invariably produces the optical phenomena anisotropy, which are observable but deemed ‘inevitable’ physical properties inherent to glass fabrication,” says Louis Moreau, Head of Technology & Innovation, AGNORA, a leading glass fabricator with headquarters in Collingwood, Ontario.
To address this phenomenon and establish guidelines for fabricators producing oversize glass, an international group of stakeholders was organized to develop a new ASTM standard test method for anisotropy measurement on glass. This task group is lead by Louis Moreau, Head of Technology & Innovation at AGNORA, along with Rick Wright, Director of Technical Services at Oldcastle Building Envelope (and ASTM C14 & C14.08 Chair).
Tristar Glass noted that they are seeing a significant increase in oversize (length), especially for the first two floors in commercial construction. AGNORA is also experiencing growth in high-end homes and retail storefronts, thanks to the trend of larger panes of glass. Specialty glass is also trending larger with the industry seeing more requests for oversize bird-friendly glass.
“We will continue to see an increase in oversize glass as North America begins to embrace jumbo sizes with new capabilities coming online from companies like Vitro and Guardian Glass who are introducing jumbo coaters,” added James Cole, Senior Project Manager, AGNORA
Next month we focus on the folks that have to take these gigantic pieces of glass and install them into buildings. It will be the glaziers’ perspective and their insights on oversize glass, including their challenges and positive outcomes.
Behind the Scenes
What goes on for a fabricator on an oversize glass job, both Tristar and AGNORA provided an example.
AGNORA was contracted to produce a high-performance glass curtain wall to serve as an enclosure to Damien Hirst’s ‘Gone but not Forgotten’, a gilded skeleton of a ten-foot tall woolly mammoth. The goal was to showcase the piece without any obstructions to the view, while maintaining the outdoor atmosphere of the tropical surroundings of the Garden of the Faena Hotel in Miami Florida. To successfully execute this project, AGNORA had to balance the need for durability and stability in the fabrication of the 4540 lbs insulated glass units with the design desired by the architectural team. The glazier, M. Cohen & Sons, partnered with AGNORA as they needed a fabricator with the ability to fabricate the walls as single units, with the largest measuring up to 129 ¾” wide x 246” long.
We recently completed a high profile job locally in Tulsa, The Gathering Place, that had a large amount of oversized glass. Our technical group did all of the analysis on the job to ensure that the larger units would meet deflection requirements, while at the same time meeting the designer’s glass wall requirements. The job was originally designed to be ¼” glass over ¼” glass for these units over 70 square feet. The final project required 3/8” outboards over 3/8” inboards throughout and ½” inboards at the corners to meet load and deflection requirements, while getting the desired look of no back up mullions!