Permasteelisa North America Crop

Davide Mangini

One of the greatest challenges architects in New York City face today is how to tie down roof pavers that not only look good but can withstand the ever-increasing high winds that pummel the city each year. On the west side of Manhattan, the Bjarke Ingles designed super tall Spiral at Hudson Yards reaches to 1,100 feet above the cityscape at the very top of the building which is just a few blocks from the West Side Highway and the Hudson River, and with 66 outdoor Terraces that sequentially wrap around each side of the building, swirling from the top to the bottom, presents a tremendous challenge to keep the Terrace Roof Pavers from blowing away. Literally.

Permasteelisa North America, the world’s largest and most prestigious custom curtain wall designer, fabricator, and installer, was tasked with unlocking the secrets to a design that has never been done before in NY. The world leader in tall challenges, the Permasteelisa design team dove headfirst into this incredible situation determined to be the first at solving this riddle.

After many months of trial and error, and a wind tunnel research project that was canceled due to COVID, PNA settled on a Kinley Raaft system. This highly specialized system requires each of the custom-sized, 5’ long x 9” wide x 4” thick formed, poured, and individually cut to sized precast concrete pavers by Zanette in Italy, to have custom-sized kerfs (slits made by a saw in the sides of each paver) that would allow Kinley’s custom created clips to screw into the aluminum “runners”/beams and turn into the pavers tying them all together to each other. The pavers now tied to the aluminum runners are now all tied together and can resist much higher wind uplift loads than if they were loosely laid on top of the pedestals, the traditional installation. However, on the 11 very high wind terraces additional concrete plinths are required to tie this paver system down to the structure to withstand winds up to 158 mph. All of this effort just for the Paver tie down system was just the beginning of the coordination required on these terraces where there is custom-made, one-of-a-kind solid stainless steel parapet railings, planters, metal grills, and pylons all designed, engineered, and fabricated by PNA.

The Kinley System hides beneath the pavers and is hidden from view completely. The gaps between the pavers allow access to the custom clips in between, which can then be turned with a simple hex key so the pavers can be removed and replaced again if additional planters are desired.