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Masonry Project |
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In 1995 an inspection of
the entire exterior surface of the Nebraska State Capitol
was conducted by consultants. They determined that
Nebraska's seasonal temperature extremes and resulting
freeze-thaw cycle had caused extensive movement and cracking
in the stone building face and roof system sufficient to
require major re-construction of these critical building
components. The results of that conclusion began in the fall
of 1997 with the start of the current Nebraska Capitol
Exterior Restoration Project. Although the entire exterior
masonry face of the building has been cleaned and
tuck-pointed at least twice in the past, the level of
restoration required currently is the most extensive since
original building construction during the 1920's. Information about the project may be obtained from the Office of the Capitol Commission by contacting: P.O. Box 94696 Lincoln, Nebraska 68509-4696 (402)471-0417
Working with the Office of the Capitol Commission on the Capitol Exterior Restoration Project are project team consultants Wiss, Janney, Elstner, Inc. of Chicago and Bahr, Vermeer & Haecker Architects of Lincoln. The general contractor for the project is Mark I Waterproofing and Restoration Company of Dolton, Illinois. Because the Capitol is a National Historic Landmark, the restoration contractor is working to preserve the integrity of the building, therefore reusing rather than replacing materials whenever possible. This conservation approach will insure that Bertram Goodhue's carefully matched limestone façade remains intact. As each stone is removed from the building it is numbered and cataloged so that it can be returned to its exact location when repairs are complete and reassembly occurs. Through a coordinated effort between the Nebraska Capitol Archives and the archives at the Indiana Limestone Company the state was able to replace damaged limestone with new material quarried from the same Indiana limestone pit from which the original stone was supplied over 80 years ago. The project was originally divided into five phases. First phase-- North Entrance Masonry Second Phase-- Tower and Turret Masonry Third Phase-- Dome and Drum Masonry and Tile Fourth Phase-- Roof of Building Base Fifth Phase-Lower Building Masonry (Floors 1-3) In each phase, the exterior masonry will be cleaned of organic growth (algae and moss). This cleaning process involves the application of a biocide to kill the micro-organisms which blacken the building face. Then a process of "facade gommage" uses air-driven glass powder to clean the dead organisms from the surface of the stone. Once the accumulated algae growth has been removed, it is anticipated that water cleaning of the building will be done every 40 to 70 years or as new growth requires. Where excessive water penetration and freeze-thaw damage require, the masonry walls will be disassembled, damaged backup brick will be replaced and internal wall flashing installed. During the reassembly process a small interior cavity will be created to allow water penetrating the walls in the future to migrate out of the walls through weep holes. The entire exterior facade of the Nebraska State Capitol will be tuck pointed and cracked stones repaired or replaced. Some of the damaged stone pieces will require the installation of patches and some will require the installation of epoxy filler to bond and seal the cracks. Replacement stone recently taken from quarries originally active in the 1920's will replace any irreparably damaged stone removed from the facade. Using a formula found in the Capitol archives, contractors will replicate the original mortar mix using sand from Platte River sand pits where the original sand was quarried. Construction began in January 1999 with the restoration of the north entrance grand staircase and porte cochere. The bison wing walls and granite steps at this entrance were disassembled, realigned, waterproofed and granite reset. Simultaneously, final plans for Phase 2 restoration of the tower took place and in the summer of 2000 scaffold was erected around the full height of the 400 foot tower. Restoration of the tower limestone veneer involved the removal of organic growth, dismantling and rebuilding of the corner turrets at the 300 foot level and parapet walls at the tower observation level, installing expansion joints at each floor to allow for movement in the tower façade and repairing areas of excessive water penetration. Maintenance of the bronze tower windows and stone tuck-pointing was also accomplished at this time. The gold glazed ceramic tile dome was cleaned and required a minimal amount of joint maintenance. While the tower was accessible the Office of the Capitol Commission took advantage of a Save Outdoor Sculpture! grant and brought in conservators to structurally evaluate, clean and patinate the 19'tall statue of the Sower and its 12' tall pedestal which crowns the Capitol. Once the tower work was completed the project moved to the south entrance and loading dock area. This entrance, south promenade stair and loading dock walls were disassembled and rebuilt during the 2003 and 2004 construction seasons. In 2005 work began on the parapet walls and roof area of the main north entrance pavilion. In the spring of 2006 restoration work will commence on the exterior of the West Legislative Chamber, the west ground floor entrance and west promenade stair. Future work will include the east ground floor entrance and promenade stair, the interior courtyards and the copper roof of the Capitol's 437 foot square base. Window restoration work in the base of the building will also be part of the project. Once work on the Capitol Exterior Restoration Project is complete the final phase will be the restoration of the Capitol's nationally recognized historic landscape, including courtyards and fountains.
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