Union Terminal looks at two years of restoration

. August 28, 2018

CINCINNATI – Union Terminal celebrated two years of active construction in its first full structural restoration. Since the restoration began in July 2016, crews have rebuilt the National Historic Landmark’s iconic fountain, restored the clock that punctuates the façade, cleaned and repaired over 6,500 square feet of historic glass tile mosaics and much more.

For the first time in its history, Union Terminal is undergoing a full structural restoration with the help of masons, historic preservation architects and structural, mechanical and electrical engineers from across the country. Originally built from 1929 to 1933, the Art Deco train station has suffered severe water damage and natural deterioration, necessitating the current restoration to address structural steel and the exterior envelope. Outdated mechanical, electrical and plumbing systems are being updated as well, making the building more efficient to operate.

Union Terminal’s iconic fountain and plaza, so critical to the historic fabric of the building, were carefully surveyed and removed over a period of four months, exposing the roof deck below for repairs. After the plaza demolition, crews waterproofed the plaza’s 120,000 square feet using tar heated to a temperature of 375 degrees applied over a thin fabric sheet and then covered with a plastic liner, insulation board and gravel. The waterproofing prevents future water penetration into the museum spaces and structure below.

With waterproofing complete in October 2017, the first of 56 concrete trucks rolled onto the plaza to begin pouring the basin of the 8,000-square-foot fountain. For the next five months, 450 cubic yards of concrete recreated the scalloped cascades and iconic shape of the fountain, paving the way for the application of a two-part polyurea waterproofing and a finishing layer of green terrazzo with a rustic finish, matching the original look of the fountain.

Beneath the fountain and plaza, crews spent six months addressing steel girders damaged by decades of water penetration through expansion joints above. To bypass the damaged steel in the ceiling of the mezzanine level, eight six-ton, 40-foot steel beams were brought in and customized on site. Using steel gantry systems, the steel beams were hoisted from the lower level to the mezzanine and then glided to their appropriate location using compressed air. The installation of the eight beams required an additional 20 tons of steel to build gantry systems and scaffolding.

On the face of Union Terminal, crews are preparing to reinstall the clock after nearly a year of repairs. The hands were removed and restored, complete with new red neon lighting along their edges. New red and amber glass are being installed across the clock’s 18-foot face and the internal gears and mechanisms have been updated and repaired to ensure the clock stays on time.

Over 225,000 square feet of limestone, brick, terracotta and concrete have been cleaned and repaired. Over 35,000 linear feet, nearly six-and-a-half miles, of silicone caulking has been removed and replaced with mortar closely matching that of the original used on the building, which will also help prevent water from penetrating the masonry into the steel structure behind it. That structural steel has been exposed in several locations for treatment. The steel was cleaned and painted with a zinc primer and two layers of acrylic paint to prevent future oxidation by stopping water from penetrating to the steel itself.

One of the most significant masonry and structural projects was the rebuild of the curved drum walls that sit just beneath Union Terminal’s half dome. The lack of expansion joints and outdated construction techniques resulted in poor thermal expansion capabilities, causing the wall’s brick and steel to slowly move away from each other, damaging the wall system. Between January 2017 and February 2018, the terracotta and brick walls were completely removed and rebuilt, replacing the interior terracotta wall with a concrete block wall with support steel woven throughout and finally covered with over 17,500 original exterior face brick.

The major remaining masonry project is the building’s west wall, which was built in the 1970s after over 450 feet of the original concourse was demolished. The wall was completed disassembled, exposing original structural steel that has since been cleaned and treated. Just this month, masons have started rebuilding the wall from the structural steel outward with a concrete block wall supported by steel woven throughout before exterior brick is installed as the final step. This work is taking place three stories above and just feet from an active rail line.

Inside Union Terminal, mechanical, electrical and plumbing upgrades are nearly complete. Outdated and aging systems have been replaced, highlighted by three new centrifugal glycol chillers, three hot water boilers and two steam boilers to heat and cool Union Terminal’s 500,000 square feet. Additionally, an updated ice storage system that uses ice to cool the building during the day has been operational for nearly a year. To diffuse the conditioned air throughout the building, 478,000 pounds of new ductwork snakes through the building and 23 new air handling units have been installed on Union Terminal’s rear rooftops, many with the help of a 450-ton crane.

Interior historic spaces are nearing the completion of their restoration to their original look and feel. New terrazzo floors have been poured in the Losantiville Dining Room, replicating the pattern of the serpentine lunch counter that once welcomed weary travelers. 22 original canvas murals that ringed the top of the dining room are undergoing final repairs by art conservators before they are reinstalled in the space for the first time in over 30 years.

In the Rotunda, the yellow, orange and silver bands of the ceiling, towering 106 feet overhead, have been cleaned, patched and painted. The red Verona marble walls of the Rotunda and concourse have been polished and cleaned, as have the aluminum strips and metalwork that adorn them.

Winold Reiss’s glass tile mosaics were cleaned and repaired over a period of six months as art conservators climbed scaffolding crisscrossing the iconic artwork. Crews completed thorough assessments of the more than 6,500 square feet of mosaics, identifying loose or missing tiles and cracks in the pigmented stucco. With that project complete, the mosaics sparkle once again in the light and reveal colors and details many guests may not have noticed before.

The upper ramps of the north and south wings (now the Museum of Natural History & Science and Cincinnati History Museum, respectively) are ready for Cincinnati Museum Center to begin the installation of new permanent exhibits. Thousands of terracotta tiles have been cleaned, plaster ceilings have been repaired and painted and restored windows and light fixtures have been reinstalled throughout.

With just months to go in Union Terminal’s first full structural restoration, crews are putting the finishing touches on the National Historic Landmark. As the fountain fills with water in the coming months and the clock finds its place back on the face of the building, guests will once again bask in the beauty of one of the country’s finest examples of Art Deco architecture and Cincinnatians will be ready to reclaim their local icon.

The restoration of Union Terminal will be complete in November 2018.

For more information, visit myunionterminal.com

Category: Museum News

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