Salt Lake City Public Library Roof Rehabilitation

Title: Salt Lake City Public Library Roof Rehabilitation

Award Category: Roofing

Project Address/Location

2210 East 400 South

Salt Lake City, Utah 84111
United States

Submitted By: David A. Rash

Company Info

Stantec Consulting Services, Inc.

600 Stewart Street, Suite 200

Seattle, Washington 98101
United States

(206) 268-7378

[email protected]

Project Description and Background: The Salt Lake City Public Library (SLCPL) opened to the public in 2003. The library is a five-story building that functions as the main branch for the Salt Lake City Public Library system. The building includes office and retail space, maintenance facilities, event rooms, and the library system’s main collection of books. The roof of the building is approximately 22,000 sq. ft. and is designed for public access. Roof areas have roof gardens, open environment public walkways and seating, outdoor patios, and terraces for social gatherings. Adjacent to the roof is a curved roof skylight system. The roof decks are covered with waterproofing systems. The library building was designed by a well-known architectural firm; constructed as an $84 million-dollar public project, which has long been considered one of the most visually striking architectural structures in the country. Visitors entering the library are greeted by an expansive interior courtyard illuminated by a stunning overhead skylight system and an immense four-story collection of books. The public accessible roof is reached from an inside glass elevator and from an open exterior six-story wrap around staircase. On the roof, visitors have a 360° view overlooking the city, and to the east, the skyline of the Wasatch Mountains. However, the building’s roof areas have been plagued by the fact that since construction the roof has leaked. For just over 20 years, due to leaks entering the building, library administrators and staff, the City, and the public were not allowed to visit some portions of the library’s upper floors during rain events, and the library roof was closed at times to attempt leak repairs. Then, in 2019, Stantec Consulting (formerly Morrison Hershfield) was retained by SLCPL to perform a roof leak assessment with the primary goal to rehabilitate the roof and to stop roof leak activity.

Scope: Back up a few years to understand the beginnings of Stantec’s involvement with Salt Lake’s rehabilitation of the main city library. Prior to the 2019 leak assessment, Stantec had managed the design and development of roof replacement projects for several of the City’s smaller library buildings. These projects succeeded in construction of modernized roof systems, installed within City budget constraints, and to result in leak-free roof systems designed to last three decades or more. Aware of this past success with building rehabilitation projects, and with the desire to once and for all end the SLCPL 20-year roof leak history, the City and library administrators again looked to Stantec for assistance. Thus, the beginnings of what would become a six-year-long roof rehabilitation project commenced. The scope of work for this project started simply enough with the roof leak assessment, but soon afterward expanded into a multi-phased project. Assessing leak activity essentially became Phase 1; the initial goal to identify the source of roof leaks and to determine repairs. Stantec decided industry standard leak assessment methodology was most appropriate to proceed. This meant that Stantec would begin with a visual assessment of the leak conditions, and if necessary, from there move to water testing and/or invasive investigation methods to identify leak sources, which would be based on nationally recognized ASTM leak investigation guidance (notably ASTM E2128). Stantec toured the interstitial space underneath the roof deck to view the actual physical conditions resulting from above leak activity, isolated leak locations, and as a result determined roof elements above deck indeed needed to be removed to more accurately pinpoint leak entrance points. Invasive investigation was then performed. Ultimately, Stantec determined roof replacement was the only avenue available to stop leaks. Conclusions from the visual observations moved Stantec into what was considered Phase 2 and Phase 3 of rehabilitation. The project expanded beyond mere roof replacement to also include redesign of the roof amenities that had contributed to leaks and to repair underdeck water damage. For Phase 2, Stantec proceeded and partnered with GSBS Architects to assemble a roof rehabilitation team to design, develop, and oversee what would become the Salt Lake City Public Library Rehabilitation Project. For the next two years, Stantec and GSBS worked creating preliminary roof replacement scopes that included GSBS concepts for new roof landscaping designs and Stantec’s compilation of roof replacement options most appropriate to remediate roof leak issues. Design concepts and replacement options were reviewed by Library administration and the public. The combined goals of the rehabilitation team, Library administration, and the public were to provide feedback as to what the SLCPL could do to improve upon the roof experience for the entire Salt Lake City community. Simultaneously, the design concepts and replacement options were provided to a general contracting firm, Paulsen Construction, to estimate construction costs via a Rough Order of Magnitude (ROM), which was subsequently delivered to the Library administration to form a comprehensive and cost-effective project budget.

Solution: Phase 3 of the project was to completely finalize the redesign of the library roof, in large part using information garnered from the Phase 2 Library and public review feedback. While GSBS finished designs for the new roof spaces and landscaping, Stantec completed the new roof replacement scope for coverage of a new roof waterproofing system. Details and specifications were created to not only reflect the actual existing roof conditions, but to also coincide with the new architectural and landscaping designs. In early 2023, construction began. Included in the overall rehabilitation project were additions of wall weather barriers, which were needed to assist with water intrusion issues, and various window sealant upgrades, which also served to eliminate leaks. However, the largest overall improvement was to cover the entire roof with a monolithic fluid-applied hot rubber waterproofing system. Earlier, Stantec had discovered that roof concrete planters, steps, and topping slabs had been installed on top of the original waterproofing system in a manner that caused water to backup and remain pooled underneath roof pavers and inside planters, rather than to drain out of the system or off the roof. These backups contributed to roof leaks, as water overflowed the top of concrete edges and entered the roof where waterproofing was absent. Stantec’s new waterproofing system was designed and installed with an accompanying new roof drainage system consisting of through-wall scuppers and additional roof drains. The new system was installed before roof overburden, such as concrete slabs, steps, roof gardens and planters, etc.--all so that water could travel underneath the new overburden in continuous, unobstructed pathways into the new roof drainage system. Where originally water backed up underneath overburden to result in leaks, it could now evacuate the roof more efficiently than had occurred for nearly two decades of service. Finally, during this Phase 3 process, additional leak locations were observed during construction and more repair solutions and designs were added. The exterior staircase, originally installed in similar fashion to the roof, also had water backup issues and contributed to roof leaks. This prompted Stantec, at the request of the SLCPL to design and develop a staircase waterproofing system to stop these additional leaks.

Value: In 2025, the Salt Lake City Public Library reopened its newly remodeled, landscaped, and waterproofed roof to the public. Visitors could now enjoy a vibrant roof experience featuring amenities designed by Stantec and GSBS: roof gardens, ADA-accessible courtyards and walkways, a children’s play area, a public-viewing honeybee enclosure, and a roof-length glass guardrail framing views of the eastern mountains. Stantec’s value to the project extended well beyond initial design. Our team began with a diagnosis of persistent roof leak activity, which continued even after construction had started. Through ongoing investigation and discovery, we identified additional sources of water intrusion and recommended scope adjustments that led to a more comprehensive solution. These included adding a wall weather barrier and replacing waterproofing systems around the exterior staircase, critical steps in resolving long-standing issues. Stantec’s relationship with the Salt Lake City Public Library remains strong. For both the City and the community, our involvement helped reduce construction costs without compromising quality. We specified sustainable materials with proven longevity, minimizing future waste and landfill impact. We also preserved the architectural elegance of the iconic building while enhancing its design for future generations. What began as a simple leak assessment evolved into a transformative project. With the roof now watertight, the public can once again read and relax above the city, enjoying uninterrupted views of the skyline and mountains. The Library and City can redirect budgets toward current maintenance and future improvements, perhaps even preparing for Phase 4 of rehabilitation, without the burden of a leaking roof. Stantec, now well established as a trusted partner by the Library staff and administration, was requested to continue SLCPL building envelope evaluation, which has since started with an assessment of the courtyard skylight system and is anticipated to include the entire envelope of the building. Stantec’s collaboration with ownership and construction professionals, our investigative expertise, and our successful repair designs brought the roof back to life. After 20 years of chronic leaks, the Salt Lake City Public Library roof is once again open: and built to stay that way.

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