Ludwig Mies van der Rohe Architectural Interior
Historic Preservation of the GSA Chicago Loop Post Office Walnut Paneling
Bernacki & Associates, Inc. collaborated to preserve Chicago’s Loop Post Office by providing condition assessments, treatment proposal, and the restoration of veneered wall panels, trims, doors, and associated woodwork.
This contract was awarded to CSOS, Inc. (Conservation of Sculpture and Object Studio), a firm that has been restoring the most prominent architectural and sculptural historic markers in the United States for over 20 years. With its experience, CSOS, Inc. provided project supervision, majority of material selection, walnut paneling restoration work, and the repairs of surrounding stone components.
The preservation architects, Harboe Architects, PC were in charge of guiding the process; Bevel Granite Company, Inc. fabricated protective granite benches; Parma Conservation Ltd., conserved the north wall painting; Speed Machine Inc. fabricated and installed protective steel elements; and Terry Dowd Inc. were responsible for panel de-installation, transportation and re-installation.
All offsite restoration was completed entirely at B&A, Inc. facilities where custom racks were designed and built to accommodate the storage of all 160 panels, trims, doors and other architectural elements prior, during, and after treatment.
The Post Office is part of the Chicago Federal Center designed by Ludwig Mies van der Rohe. The building was completed in 1973. It is a single-story building that rises 27 feet above grade with two levels below ground. The structural system is arranged on a grid of 28 square feet with a vertical floor to ceiling height of 24 feet. The exterior flat black graphite painted steel structure with floor to ceiling windows allows the outside in, with views of the surrounding plaza. The granite pavement on the exterior, continues through to the interior, furthering the open effect of the design. The postal operations and services are enclosed within a series of walnut veneered panels while the public lobby extends around the perimeter of the building. The walnut veneered panels create a warm, traditional contrast with the juxtaposition of the sleek glass, granite and steel exterior. This type of veneered paneling is found in many other mid-century lobbies as well as other Mies’ buildings. The paneled walls extend beyond the corners to create the effect of wall planes sliding past one another, which is also typical in other works by Mies. The post office boxes are located on the west end of the building. These are set behind a wall and feature walnut panels above and Rockville granite surrounding the aluminum framed boxes. The iconic red 53 foot tall stabile, Flamingo, by Alexander Calder, is installed in the Federal Plaza next to the building.
The Chicago Loop Post Office interior South East corner view | Photo courtesy of GSA
Project Scope
Bernacki & Associates Inc. was first selected to provide its expertise to assess and confirm the condition, as well as the methods and materials originally used in the fabrication and installation of panels. Based on the results they then and established a treatment guideline.
The panels were originally fabricated by U.S. Plywood Corporation as Weldwood Architectural Grade Paneling. Each panel was labeled on the reverse side by the manufacturer. The veneered walls suffered from years of bustling commercial use, along with exposure to water, humidity, and contact with postal equipment. The panels exhibited varying degrees of damage. Some were warped and out of alignment, and in some cases, where the more severe damage prevailed, the panels had large areas of missing veneer. The condition of the panels called for various solutions that would address the unique condition of each piece, while ensuring an overall homogeneous result for the collection as a whole. All of the panels had to be de-installed, treated, reinstalled and reset to proper alignment. Four panels were specifically chosen and used as the overall reference for their varying degrees of deterioration: color faded from exposure to ultraviolet light, veneer delamination, deep scratching and gouging to veneer and substrate, water staining, nail holes, and the stability of the veneer which had potentially been compromised during previous attempts to repair.
The goal of the treatment was to retain as much of the existing material as possible; repair and consolidate the compromised surface. Only as a last option was material replaced and carefully integrated.
Loop Post Office interior - South East corner view of the wall paneling before treatment, with one darker panel previously treated as reference for the severe degree of deterioration | Photo courtesy of GSA
South East Corner panels viewed after treatment, with protective architectural elements that were added to shield original veneered panels and trims from potential damage: metal door panel, guard rail, corner guards, and a granite bench | Photo courtesy of GSA
Detail of the West wall panel section showing excessive water damage staining and dirt along the bottom. There is also unoriginal protection rail and white corner guards installed years after the building was completed. | Photo courtesy of GSA
West wall panel wall viewed after treatment. Water staining and dirt are removed, the panels are refinished, the unoriginal rail is eliminated in this location as the Post Office carts do not enter this area and there is no risk of abrasion caused by equipment. The previous rail was installed directly on the veneered panels, which created additional damage to veneer and deep hols in the substrate. This damage was addressed by infilling and matching to the surrounding area as much as possible. New elegant steel guards protect corner trims from damage. | Photo courtesy of GSA
North wall detail with visible horizontal scratches along multiple panels as a result of contact with the Post Office equipment. | Photo courtesy of GSA
North wall segment viewed after conservation and preservation effort made by the installation of the stainless steel rail attached to the wall in the narrow reveal spaces without damaging the panels. | Photo courtesy of GSA
Process
The collection of approximately 340 3’-5” by 7’-10” panels were carefully removed and transferred to Bernacki & Associates, Inc. facility for repairs. The removal, packing, and transportation of the panels was not an easy task, as their size, condition and the volume required special attention and handling, before the treatment could begin. A detailed identification and tracking system was created to ensure that all the panels and elements could be reinstalled in the same location from which they were removed.
Upon removal of the panels, the following treatment was performed:
The compromised finish was removed.
The water and embedded grime stains were removed.
The depth of the scratches was reduced through localized steaming.
Deep gouges were infilled and levelled.
Areas of veneer loss and severe damage were infilled with new veneer to integrate the original veneer in color and grain patterns, connecting to the original sections with minimum alterations.
The panels were then finished to evenly match in color depth, darkness and sheen.
It was determined that it would be invasive to remove select components of the paneling. The veneer within the reveals, trims, and corners were treated on-site. Upon completion of the treatment of each phase, the panels were carefully documented, packed, and reinstalled. Great attention was given to the placement, alignment and orientation. The work was completed without interruption to the operations of the Post Office. It was performed overnight and required the use of a fume extraction system to eliminate the odors from chemicals used.
To help deter further damage to the paneled areas that were at greatest risk of contact with postal carts, a stainless steel railing and corner guard system was designed and installed.
This wide angle photograph captures the extent of deterioration of the veneered panels and the adjacent door caused by contact with metal Post Office carts over many years. | Photo courtesy of GSA
The same area after conservation and the installation of the stainless metal guard rail along the wall and panel protecting the door | Photo courtesy of GSA
Close up of the rail breaker (looking downward) placed between the preserved panels without damaging restored surface
Preserved railing breakers cutouts for…, stored in archival sleeves
Door detail before treatment | Photo courtesy of GSA
After treatment | Photo courtesy of GSA
Detail of veneered panels and trims at floor level with visible damage from contact with Post Office carts and cleaning equipment | Photo courtesy of GSA
Restored panels and trims; granite bench and metal corner guards installed for protection | Photo courtesy of GSA
Abrasions and water damage to veneered panels at the floor level | Photo courtesy of GSA
After treatment | Photo courtesy of GSA
CLOCK
The project allowed for the exciting discovery of two original wall clocks that were previously obscured by a more recent clock. The existing clock numbers were cleaned and reinstalled, and new replica faceplates and hands were created and installed.
Unoriginal clock | Photo courtesy of GSA
Restored and functional original clock | Photo courtesy of GSA
Through attention to detail, commitment to craftsmanship and efforts to ensure the longevity and functionality of the paneled interior, the Loop Post Office can be used and aesthetically appreciated for future generations.
In studio during treatment
North phase panels stored at Bernacki & Associates studio during treatment and marked for precise identification
Veneered panels in custom drying racks at Bernacki & Associates, Inc. facilities. Each coat of shellac was allowed to dry before the subsequent sanding and the next phase of finish application.
