IFMA Facility Fusion 2011 8.06 “Architectural Preservation at Boston College Campus: A Systematic Approach” Wendall C. Kalsow, AIA, McGinley Kalsow & Associates Ivan Myjer, Building and Monument Conservation Evan Kopelson, Vertical Access LLC / TPAS LLC Online Conference Proceedings Submittal Introduction Founded in 1863, Boston College is a Jesuit institution of higher learning, originally located in Bostonʼs South End. In 1907, Father Thomas Gasson, who had recently become BCʼs president, decided that the cramped, urban surroundings of the location were unsuited to the expansion of the college, and started the process of moving the campus to Chestnut Hill, six miles west of Boston. Charles Donagh Maginnis of the Boston architectural firm of Maginnis and Walsh won an architectural competition for the master plan of the new campus, Design Competition Winning Vision of Boston College Maginnis & Walsh (1909) which included twenty buildings in an English Collegiate Gothic style. By 1909, construction of the first building, originally known as “Recitation Hall,” then the “Tower Building,” now “Gasson Hall” had commenced. Completed in 1913 the main building stood as the only completed portion of the campus plan for some years, until funds were raised to construct additional buildings. Among the other early buildings forming the Chestnut Hill campus of Boston College are St. Maryʼs Hall (1917), Bapst Library (1922) and Devlin Hall (1924). Lyons Hall, the fifth building included in the current study, was constructed in 1951. Since 2006, McGinley Kalsow & Associates, Building and Monument Conservation and Vertical Access have been working with the Capital Projects Management Department of Boston College to investigate, document and design repairs to the historic campus buildings. The project team has taken a systematic approach involving hands- on investigation, detailed documentation of existing conditions, thorough analysis of collected data, and preparation of comprehensive treatment recommendations and construction documents. Beginning with the hands-on investigation of Postcard ca.1913 – Gasson Hall 1 Gasson Hall in 2006 and continuing with the documentation and assessment of St. Mary's Hall, Bapst and Burns Library, Devlin Hall and Lyons Hall in 2007, the project team has collected detailed information on the existing conditions of the group of buildings at the central campus area of Boston College. Conditions of the cast stone, limestone, puddingstone and granite masonry of these buildings were mapped out unit- by-unit using TPAS, a direct digital documentation system. The data was then evaluated to prepare treatment recommendations and assist Boston College in prioritizing future capital repair projects for the historic buildings. The first project undertaken was the restoration of the landmark Gasson Hall at the center of the campus. The buildings designed as part of the first phase of construction for the campus are masonry buildings with puddingstone used for the field of the exterior walls and a second material used for trim and ornament. Puddingstone is a sedimentary stone, but one without well-defined bedding planes. Structurally, it is more of a conglomerate with a variety of large inclusions in a relatively hard matrix. It was quarried locally, and commonly used in stone foundations and walls in the Boston area. At Gasson Hall and St. Maryʼs Gasson Hall – Construction Photo ca. 1912 Hall, cast stone is used for the decorative units, including the quoins, corner piers, window surrounds and tracery. Some of the cast stone had a rilled tooling pattern that would have given the appearance of natural stone. Limestone was used for trim and ornament of Bapst Library and Devlin Hall, instead of cast stone, and is the primary exterior material at Lyons Hall. Investigation and Documentation In 2006, the Capital Planning and Engineering Department of Boston College requested proposals for architecture/engineering services for the Restoration of Gasson Hall Exterior Façades project from an invited group of consultants. The design contract was awarded to a project team led by McGinley Kalsow & Associates with Building and Monument Conservation, LeMessurier Consultants Structural Engineers and Vertical Access. The first part of the Gasson Hall project entailed a hands-on investigation of the building to document existing conditions. A combination of industrial rope access and aerial platforms (boom lifts) was used for the hands-on survey. At the tower, VA technicians used industrial rope access to perform the up-close examination. McGinley Kalsow and Building and Monument Conservation used aerial platforms to survey the lower portion of the building. One of the tools used during the investigation of the tower was live-feed video. At the outset of the investigation, VA technicians surveying the exterior tower used a hand-held video camera connected to a monitor at the base of the tower to review conditions with the entire project team. Using two-way radios, the project team was able to ask questions of the VA technician operating the camera and clarify findings about specific conditions. In this way, the entire project team could gain a consensus understanding of the issues affecting the deterioration of the materials, structural condition and ultimately the restoration of the building. 2 The project team used tablet computers and the Tablet PC Annotation System (TPASTM) to record existing conditions at both the tower and base of Gasson Hall. Vertical Access developed the Tablet PC Annotation System (TPAS) to input annotations, graphics and numerical data directly into AutoCAD, on site, using tablet computers and digital cameras. Direct digital documentation eliminates the two-step data entry process traditionally used during condition surveys with paper drawings and pen annotations, adding efficiency to the reporting process and eliminating transcription errors during redrafting. Working within the AutoCAD program, TPAS employs standard commands in conjunction with customized programming. Among the features employed using TPAS that are native to AutoCAD are block libraries, blocks with attribute tags, AutoCAD design center, selective display of layers and attribute extraction to spreadsheet or database programs. Custom programming provides automatic calculations of the lengths and areas of conditions drawn and inserted into the AutoCAD drawing and on-site naming and hyperlinking of digital photographs to automate the process of photo capture and cataloging. Vertical Access Technicians Rappelling Down the Façade of Gasson Hall TPAS is a tool used not only for collecting data in the field, but also for managing and organizing the data in the office. All condition information in the AutoCAD drawing is managed by layer to facilitate the control and visual display of information. This tool can help with the interpretation of condition drawings, identification of fault patterns and assessment of building conditions. TPAS also allows for the export of all numerical condition information into a generic data file format that can be imported into any spreadsheet or database program for analysis of conditions, calculation of take-offs, creation of cost estimates for project scoping and development of phasing or scheduling scenarios. The investigation of Gasson Hall served as a model for work that was undertaken the following summer to investigate and document the existing conditions of four additional buildings on Boston Collegeʼs Chestnut Hill campus. In each case, the investigation was performed using a hands- on approach. At Bapst Library and St. Maryʼs Hall, a combination of rope access and aerial platforms were used for the close-up examination of existing conditions. At Devlin and Lyons Halls, aerial platforms were used for the hands-on investigation. In all cases, close interaction among members of the project team and Photograph of core drilled hole showing partial deterioration documentation of existing conditions using of cast stone ¾” from the face of the stone TPAS were integral to the investigation. 3 Analysis and Assessment The building in most urgent need of repair was Gasson Hall. The survey data collected by the team and documented using TPAS, was analyzed by the design team in order to identify patterns of masonry deterioration as well as to evaluate the efficacy of prior repairs to the cast stone trim units. The analysis determined that the rate of deterioration in the cast stone had advanced rapidly over the past 35 years. Our analysis also indicated that, since the two prior restoration efforts had not succeeded in arresting the cast stone deterioration, there was a very good possibility that the problem with the cast stone was the result of an inherent fault. To test our hypothesis, cores were taken from units that were weathered but still sound as well as from units that were severely deteriorated. Following a visual examination, the cores were sent to a lab for petrographic analysis and reverse engineering of the mix. There are several factors resulting from the fabrication of early 20th century cast stone that can produce systemic failure of the units. Among these are alkali silica reaction, loss of carbonation and a susceptibility to freeze-thaw damage resulting from a lack of air entrainment in the mix. It was this last factor that John Walsh, a petrographer, currently with Highbridge Materials Consulting, identified as the principal cause of the ongoing cast stone failure. Secondary causes included cracking