The construction techniques used in the building of Union Terminal between 1929 and 1933 and the subsequent interventions over eight decades present a variety of challenges to the masons and preservation architects addressing them. The outdated techniques have resulted in significant water damage; bulging and cracking of the exterior limestone and bricks, and rust on the structural steel. Crews work layer-by-layer, removing limestone or brick, then the terracotta tile underneath before finally reaching the structural steel, assessing and repairing each layer as they go. Once treated with a combination of paints, the steel is covered by interior brick and face brick or limestone with expansion joints added to prevent future cracking and bulging. In addition to ongoing treatment of structural steel and exterior masonry around the building, here’s a look at the work coming up this month.
1. The historic fountain and plaza, so critical to the historic fabric of the building, is in the process of being temporarily removed. A small crew of skilled workers are meticulously removing all historic limestone, granite and fountain fixtures, cataloging them and storing them in a secure location while work continues on the plaza. Once the removal of historic stone and fountain finishes is complete later this spring, crews will begin waterproofing the area below (which forms the roof for portions of the Union Terminal’s lower level) to prevent future water damage. Once complete, the fountain and plaza area will be rebuilt in a precise manner.
2. A crane will begin removing limestone blocks from the pillars supporting the iconic clock on the front of the building. Once the limestone is removed, the steel underneath will be cleaned and treated while the limestone is repaired.
3. A 550-ton crane with over 330 feet of reach will remove nine air handling units from the roofs, including those on the wings of the building that house the Museum of Natural History & Science and Cincinnati History Museum, the historic Losantiville Dining Room and atop Tower A, the original control tower of the train yard. In the coming months, new air handling units will be installed on rear rooftops and the rear mechanical yard that will more efficiently cool the building.
4. New classroom space is being roughed out with new walls and ductwork on the Lower Level inside the Cincinnati History Museum. The classrooms will continue to take shape and will offer expanded space for interactive programming.
5. A concrete slab is being poured in a formerly unused space with a dirt floor. The space, located adjacent mechanical and storage areas, also shares a wall with the Museum of Natural History & Science. The new concrete floor stages the space for future exhibits and/or collections.
Number to know: 14 – The 140 cubic yard concrete pour over the dirt floor will require a minimum of 14 truckloads of concrete. That concrete will then be trekked indoors to the pour location, a half yard at a time, with motorized buggies.
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