The High Museum of Art – Weiland Pavilion and Anne Cox Chambers Wing Roof Replacement

Title: The High Museum of Art – Weiland Pavilion and Anne Cox Chambers Wing Roof Replacement

Award Category: Roofing

Project Address/Location

1280 Peachtree Street NE

Atlanta, GA 30309
United States

Submitted By: Bryce McQueen

Company Info

Merik, Inc.

3225 Shallowford Road
Suite 820
Marietta, GA 30062
United States

770-565-3016

[email protected]

Project Description and Background: The Wieland Pavilion and Anne Cox Chambers Wing are part of a 177,000 square foot expansion of the Robert W. Woodruff Arts Center, Inc.’s High Museum of Art, and were completed in 2005. Designed by renowned Italian architect Renzo Piano, in collaboration with Atlanta based Lord, Aeck, and Sargent Architects, the expansion features three buildings clad in white aluminum wall panels and low slope roof areas containing 1,000 custom tubular skylights fitted with solar deflecting light sails that are intended to provide the museum with uniform diffused interior natural lighting conditions. The Wieland Pavilion contains four levels with 800 skylights, and the Anne Cox Chambers Wing contains three levels with 200 skylights. Both wings function primarily as art galleries, displaying a portion of the High’s permanent collection, and rotating special exhibitions. Merik, Inc. was hired by the Owner to serve initially as a roof consultant to determine the cause of and develop repair recommendations for a series of persistent leaks that had occurred within the building for years. Numerous investigative techniques were used, in conjunction with other professionals, and it was ultimately determined that the existing original roof systems had completely failed and could not be effectively repaired. Over the course of the project, Merik’s role as consultant morphed into that of roof system designer, construction contract administrator, and full-time quality assurance construction observer for various new custom roof solutions. Throughout our involvement, Merik’s primary directive from the Owner was to respect and maintain the museum as much a piece of art as the artwork that it possesses. Over the course of an approximately two-year investigation, design, and roof construction period, the leaks within the building finally stopped and the Owner was provided with a new permanent high performance roof solution.

Scope: The skylight roofs consist of low slope rectangular-shaped areas composed of a cast-in-place concrete and metal composite structural deck, extruded polystyrene insulation, and a sloped reinforced concrete topping slab that surrounds the array of custom tubular skylights that was previously covered with a polyester resin-based liquid roof system. The non-skylight roof areas that are adjacent to the skylight roof areas are comprised of an existing single-ply thermoplastic polyolefin (TPO) roof membrane over roof insulation and a sloped structural concrete roof deck. The perimeter of each roof area consists of custom sheet metal fabrications and railings that are integrated with the exterior metal wall panels. As the consultant, the Owner relied on our expertise to guide them to a permanent solution after several failed repair attempts to correct the pervasive leak issues. Very early on in the project it was determined that the extraordinarily large number of skylight penetrations, varying drainage conditions, and perimeter edge detailing and expansion joint design would present a multitude of opportunities for water infiltration through the roof system and into the building. Unfortunately for the Owner, our investigative work determined that each of these conditions was in fact contributing to the influx of water below the roof system. In addition, the existing fluid-applied roofing system had likely failed very early on following its original installation due to its likely application over a concrete topping slab with elevated moisture content. A wide variety of field and laboratory tests were performed by Merik and others to both determine the mode of failure, as well as to guide us to solution. These tests included a combination of destructive exploratory openings in the roof membrane system and concrete topping slab, as well as non-destructive ASTM C1153 Infrared (IR) roof moisture imaging, ASTM D7954 non-destructive impedance moisture surveying, and ASTM D7877 electronic leak detection (ELD) testing methods. In addition, ASTM D4541 and D7234 coating adhesion testing, ASTM C856 petrographic examination, and ASTM C1583 tensile bond strength testing of coating systems was performed and used to demonstrate the failure of the original roof system. After an intensive investigation and conceptual design period, Merik was authorized to serve as Architect and design professional for a complete roof replacement system. Custom high-performance solutions were developed for both the skylight and non-skylight roof areas, with nuanced design modifications that would increase the performance of the roof system without compromising the architectural appearance or character of the building. As the consultant, we understood that leveraging the expertise and capabilities of our trusted industry partners would also be an asset to the Owner. Through early coordination with a trusted roof system manufacturer we felt could deliver our intended solutions on an extremely high profile project, our collaborative approach yielded tremendous investment from all sides of the table. Ultimately, we believe the high-level focus on results-driven decisions taken by the entire project team and buy-in from the Owner is what allowed the project to be a success.

Solution: The design for the skylight roof areas generally consisted of removal of the existing fluid-applied roof membrane system; preparation of the existing concrete topping slab to include removal of an existing cementitious overlay with excessive entrained air voids; preparation of 1000 metal skylight tubes and other perimeter conditions; and installation of a new fully reinforced multi-layer polymethyl-methacrylate (PMMA) high-performance traffic bearing roof membrane system. The work also included new reinforced membrane wall flashings, custom profile manufactured sheet metal parapet wall copings, custom access ladders, and other penetration flashings. The design emphasis for the skylight areas was to provide a replacement fluid-applied roof membrane system, with significant improvements over the original membrane in the areas of tenacious membrane adhesion, durability, expansion capability, wearing and weathering resistance, and finish appearance. To achieve this, the project team performed a full-scale in-place mock-up of multiple skylights to demonstrate the effectiveness of the solution, perform quality assurance field testing to verify the system performance compared to the established design metrics, and offer the Owner an opportunity to verify the final aesthetic would meet the architectural requirements for the building. The design for the non-skylight existing TPO roof areas consisted of a complete roof replacement down to the structural sloped concrete roof deck; and installation of a new torch-applied modified bitumen temporary roof membrane, vacuum sealed high R-value insulation, cover board, and a multi-ply hybrid roof system consisting of a modified bitumen base ply and PMMA high-performance roof membrane system finish. The design also included new integral high-performance double-layered expansion joints, roof edge securement, membrane wall flashings, custom sheet metal copings, and other miscellaneous items. The primary challenge for the non-skylight areas was to overcome what we believe was a fatal original design flaw, which was the detailing of the hundreds of knife edge railing penetrations at the roof edge that are integral with the exterior metal wall panels and required roof membrane penetration at each location. In order to achieve this, we reduced the height of the original roof assembly to allow construction of a roof edge curb to receive the perimeter expansion joint system and a new custom sheet metal coping profile, all while maintaining the original profile of the roof edge as viewed from the building exterior. Accomplishing this, while also meeting the current energy code requirements, meant turning to a high R-value vacuum insulated insulation panel system and custom fabricated double layer polymer expansion joint system. These components were carefully designed and verified through the shop drawing review process. The use of state-of-the-art roofing materials allowed for us to create significant improvement in the perimeter detailing and not repeat the cause of the original leakage issues. In addition, the use of a durable temporary roof system eased the ability to install larger areas of new contiguous roof components, and the hybrid finished roofing membrane system allowed for a powerful combination of long term expected roof performance and Owner-approved aesthetics.

Value: The success of the High Museum project was entirely driven by the consistent and intensive collaboration from the entire team to achieve the Owner’s primary objectives, with the understanding that failure would not be an option. In order to achieve this, we focused on a few key components that were maintained from the beginning of the project to the end. These primarily consisted of performance driven design solutions, quality assurance verification and testing, construction period quality control, consistent and effective communication, and quick issue resolution. In order to ensure this was maintained, Merik took an active role in leading each aspect of the project. One of the more unique aspects of the project that Merik required of the awarded contractor was to perform a pre-construction full-scale training session and mock-up installation with the designed system manufacturer. Over the course of several days, full-scale skylight replicas were constructed in the contractor’s warehouse and the manufacturer provided detailed installation training to each worker who would be present on the project. This allowed for system application improvements and lessons learned by each person on the project, so that a proper installation could be achieved starting on Day 1. This also allowed for everyone to get used to roofing in confined conditions, as the skylights are positioned only inches apart. Mock-up conditions were then retested in the same manner as the investigative testing to verify their performance. During construction, Merik lead regularly scheduled OAC meetings with the project team, provided construction contract administration, and also provided full-time construction observation to document the application of 100 percent of the roof system and verify quality assurance consistency over the more than one year construction period. Daily reports and issues logs by both the contractor and construction observer allowed each aspect of the construction to be documented and verified for consistency and allowed the Owner the ability to communicate the progress of the project with building personnel and arrange daily work area closures in the museum spaces as needed. The value of the consultant on this project was in providing the Owner with the needed expertise, high performance roof solutions, and team-driven collaborative approach needed to resolve an extremely complex issue where all previous attempts had failed. This project would not likely have been as successful without the complete buy-in from the consultant, contractor, systems manufacturer, and the resources of the Owner to allow us to meet their strict requirements. Decisions were driven by data and testing, installation practices were routinely verified through quality assurance and quality control, and consistent communication eased the headaches of the Owner in coordinating a difficult roofing construction project over an active art museum.

Project Images

Additional Info: Additional photos of the completed roof can be found here, if desired: https://app.box.com/s/vaqfeas0kfg7pvwm7u605y1xdmyck28h We would like to thank our industry partners who were key members of the project team in the success of this project: Siplast Situra Kingspan Metal Era A special thank you to TL Gowin & Company, whose professionalism and commitment to quality, value, and safety were unbelievably appreciated by the entire team! As a current update to the project, despite the devastating impact and extraordinary rainfall of Hurricane Helene on Georgia and the southeast in late September, the High Museum Weiland Pavilion and Anne Cox Chambers Wings remain dry.

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