Building the Eighth Floor Alumni Roof Terrace at 41 Cooper Union

Architype presentsJulie Dillon
Julie Dillon is the Communications Director at Bison Innovative Products and developed their how-to planning and installation videos among other accomplishments. ...
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One of Cooper Union’s iconic features is the Alumni Roof Terrace located on the eighth floor of the new 41 Cooper Square building. Creatively integrated into the design, this dramatic terrace showcases engraved names of alumni contributors in beautiful black granite pavers. Cooper Union’s Alumni Terrace exemplifies the goal of modern rooftop design – to create highly functional spaces that are also interesting and beautiful.

Creating pedestrian decks on rooftops presents unique challenges. Questions often arise: How to install a deck without compromising the waterproofing system? How to level the deck and accommodate complex slopes and penetrations? How to access the roof system below for maintenance and repair? Architects know that the right deck installation can not only protect and enhance the life of costly roof systems, but create dynamic outdoor spaces that increase the value of the project.

Before Bison Deck Supports, installing level pedestrian decks on rooftops was a challenging proposition. Damaged waterproofing systems, excessive labor costs and maintenance problems were common. In the mid-nineties Bison introduced the first adjustable screwjack pedestal system into the U.S. market. Today, Bison Deck Supports are manufactured in the USA and are available worldwide. Bison pedestal systems are designed to provide maximum design flexibility while also making installation fast and efficient. Each pedestal supports a corner of four pavers. A simple turn of the pedestal accommodates for both height and slope. Spacer tabs uniformly align pavers and provide space for water to adequately drain.

What holds the deck in place? The Bison Pedestal Paver System relies on gravity and tight perimeter containment to contain the deck – there is no mechanical attachment. Pavers sit on top of Bison pedestals and create an air permeable deck whose joints allow water to drain, and the wind to flow above, below and around the deck surface thus helping to equalize uplift forces and restraining movement of the deck and tiles.

How much weight can the pedestals support? The pedestal system selected for 41 Cooper Union’s granite terrace was the Bison Versadjust Adjustable Deck Support. The Versadjust system, Bisons’ industrial quality product line, has a weight bearing capacity of 1250 pounds per pedestal (FS3), a broad footprint for maximum stability, and impervious polypropylene construction that withstands freeze thaw cycles and resists mold. The eighth floor terrace at 41 Cooper Union demonstrates an installation where weight bearing capacity of pedestals was crucial. Each black granite paver was two foot square by two inches thick and weighed approximately ninety five pounds. Versadjust pedestal features helped the contractor set and fine tune the adjustment of these heavy pavers when loaded.

Added to the normal installation considerations, the eighth floor terrace at Cooper presented unique complexity. “Since the names on the pavers needed to be lined up, uniform installation was important,” says Hugh Tanchuck of North Shore Monuments and North Shore Architectural Stone. “To install this deck efficiently, we needed to use a pedestal system that was easy to handle so we could manipulate everything quickly.” Versadjust pedestals are equipped with a base leveling system that accommodates up to one inch per foot slope and makes precise slope adjustments quick and easy. This was especially valuable when installing the thick, heavy granite pavers on the eighth floor rooftop terrace at 41 Cooper Union.

What is the overall height range of the Bison system? Fixed Height supports are available from one eighth inch (1/8”) to 1 1⁄4 inch high. Adjustable pedestals range from 1 1⁄4 inches to 24 inches and excess heights from 24-36 inches can be reached using the patented Bison Brace System. The Versadjust Quick Clip Coupler © (patent pending) increases the speed and efficiency installing pedestals at heights over 9 inches.

As demand increases for pedestrian decks on rooftops, use of a proven and trusted installation technique system like Bisons’ offer the building owner a solution that makes sense. For over 15 years, Bison Deck Support systems have transformed the way beautiful spaces are created on rooftops or over occupied space. Bison Deck Supports contain 20% Post-Industrial Recycled Material and are manufactured in the U.S.A. In addition to Deck Supports,
Bison offers Ipê Wood Tiles and Cube planters and products can
contribute to LEED points. Bison offers in-house take-off service and
free sample pedestals at or call at 1-800-333-4234

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