Francis Marion Hotel Restoration

Title: Francis Marion Hotel Restoration

Award Category: Exterior Wall

Project Address/Location

387 King Street

Charleston, SC 29403
United States

Submitted By: Robert McDowell

Company Info

WxTite LLC

6909 International Drive
Suite 106
Greensboro, NC 27409
United States

(336) 209-7202

[email protected]

Project Description and Background: The Francis Marion Hotel, located in downtown Charleston, South Carolina, is not just a building, but a living piece of history. Built in 1924, this majestic twelve-story structure was, and still is, an architectural marvel. Named after Revolutionary War hero Francis Marion, also known as the "Swamp Fox," the hotel embodies a legacy of resilience and grandeur. The structural frame consists of twelve floors of cast-in-place concrete columns and poured concrete decks with a combination of hollow terra cotta block units and three-wythe thick brick, filling the voids between the columns. Structurally, the building appears to be two buildings connected perpendicularly at the intersection of King Street and Calhoun Street. The King Street elevation contains commercial aspects, such as a flat roof with a steel-inset "penthouse" structure. This structure once housed a radio communication technology facility and was the location of a radio broadcasting studio. The Calhoun elevation appears to be more residential with a wood-framed gable roof, extending the entire elevation. However, these two elevations look seamless from the ground with three levels of terracotta cornices, friezes, and architraves seamlessly surrounding the top stories of the building. Throughout its 100 years of history, the hotel has undergone various improvements and maintenance that coincides with the times and regulations. Improvements include the installation of the cantilevered stairwell that connects the 11th and 12th floors, installed after the completion of the original construction to comply with hotel egress regulations.

Scope: In 2020, due to various issues such as water intrusion, visual wearing, and deterioration, the ownership initiated a comprehensive assessment of the building envelope and structure. The design and scope generation for the restoration required extensive historical research on the construction and engineering of the building, existing material petrographic analysis, compressive strength analysis, and mathematical engineering — all geared to the standards of the ICRI, the 2016 building code, and the City of Charleston. Standing over 180 feet above Charleston's streets, the hotel presented unique challenges from the very beginning. Traditional inspection methods wouldn't suffice for a structure of this magnitude and historical significance. The team turned to cutting-edge drone technology, combining it with meticulous historical research, public records, observations from the Historic Charleston Foundation, and countless hours of watching the building during rain events to understand exactly how water was finding its way inside. The investigation revealed a building that had many architectural changes over the decades. During the 1930s, when the 12th floor was transformed from a dance hall into hotel rooms, engineers had added a cantilevered stairwell connecting the 11th and 12th floors — an architectural afterthought that would later become one of the project's greatest challenges. This project can be divided into 4 primary phases, each with its own inspection, evaluation, scope generation process, access, and restoration process. The restoration began with the King Street elevation, where the team initially relied on drone technology, binoculars, and keen observation to assess the scale of problems with the brick veneer and ornamental terracotta features. The preliminary analysis suggested that water intrusion was primarily caused by deteriorated skyward-facing mortar joints in the terracotta, organic growth promoting further water penetration, and failing window perimeter sealants. However, as with many restoration projects involving century-old buildings, direct access revealed surprises. When four swing stages were deployed to reach the affected areas, the scope expanded dramatically. The team discovered corroded window lintels beyond acceptable tolerances, rotted wood windows, and unsound brick and terracotta masonry units that hadn't been visible from the ground level. The breakthrough came at the 10th floor windows, located directly beneath the building's largest terracotta outcrop features. Here, the corroded lintels told a story of water intrusion that had been building for decades. All water infiltration from above was funneling to this critical water table, where it either pooled and contributed to lintel corrosion or found its way into the building through 10th-floor ceilings. With the root cause identified, the team implemented a comprehensive solution: organic growth removal, mass brick repointing, brick replacement, stitch tie installation, terracotta unit repairs, glazing, mortar joint replacement, lintel replacement, through-wall flashing installation, and the application of a complete masonry water-repellent system. The most challenging aspect was accessing a beam that hung precariously over the building's back inside corner. This required constructing a complex scaffold and swing stage system that pushed the boundaries of safe access engineering—a testament to the ingenuity required when working with historic structures that weren't designed with modern maintenance in mind.

Solution: The most technically demanding phase involved the cantilevered stairwell—a 1930s addition that had become visually and structurally concerning. Built as an afterthought when the 12th floor was repurposed, this unusual, cantilevered cast-in-place concrete beam and brick structure extended beyond the building envelope between floors 11 and 12. Ninety years of weather and wear had taken their toll. The concrete beams showed visible deterioration, brick lintels were failing, rebar was exposed and corroded, roof leaks were evident, and the brick veneer was shearing. The situation was serious enough that the ownership team closed the 12th floor to guests until the structural integrity could be restored. Accessing the exterior of the stairwell for repairs was a monumental feat. Working between 150 and 180 feet above the sidewalk, the team constructed system scaffolding that partially rested on the roof of the adjacent College of Charleston Lightsey Center. This required careful analysis and engineering to ensure that both the neighboring building's roof and the shoring system could withstand the forces involved in the restoration process. The complex part of this challenge was inspecting and analyzing the cantilevered beam system without any original drawings or designs. The team embarked on a comprehensive process of destructive testing and analysis to understand the forces and weights involved. Every aspect was methodically evaluated: the overlap of concrete beams protruding into the building, connection types to the existing structure, thickness and width of each beam and slab, rebar gauges and utilization, structural integrity of remaining reinforcement, weight of the three-wythe thick hollow terracotta units, roof system weight, and bearing capacities of all components. Once the structure was properly shored with an enhanced scaffolding system, concrete cores were extracted from sacrificial locations throughout the beams and floors. These samples underwent compressive and petrographic analysis to determine original construction materials, molecular composition, and structural strength characteristics. The engineering administration conducted extensive research into historical compliance codes, seismic requirements, the 2016 International building code, and City of Charleston regulations to design the most robust, code-compliant restoration possible. Exposing the concrete beams required removing the remnants of corroded brick lintels while simultaneously supporting the brick above. This challenge was met by installing over 500 helical wall and stitch ties — a complex web of reinforcement that maintained structural integrity throughout the process. The concrete beam restoration showcased the team's expertise in modern repair techniques. All rebar corrosion was exposed and assessed, with more than 20 linear feet requiring replacement with stainless steel reinforcement suitable for the coastal environment. An intricate combination of stainless-steel helical ties, rebar, and stirrups was installed to create a reinforcement system that would withstand another century of Charleston's coastal weather. Following municipal and engineering inspections, the team executed a complex forming and pouring process using self-consolidating concrete combined with overhead and vertical patching techniques. After seven days of wet curing, the hotel regained access to its 12th floor, and the project continued with brick lintel installation, through-wall flashing, brick replacement, and miscellaneous haunch repairs.

Value: The Francis Marion Hotel restoration project exemplifies why engaging qualified consultants is essential for success, particularly when dealing with a century-old structure of significant historical and architectural complexity. The project's success hinged on specialized engineering knowledge that hotel ownership couldn't possess in-house. The 1930s cantilevered stairwell presented an extraordinary challenge—a structural addition with no original drawings or design documentation. Engineers conducted comprehensive destructive testing and analysis to understand the forces, weights, and structural integrity of this unique feature. Without this expertise, attempting repairs could have resulted in catastrophic failure of a structure suspended 150-180 feet above Charleston's streets. The 12-story building's height and historical significance demanded sophisticated evaluation methods beyond traditional inspection techniques. Consulting engineers combined cutting-edge drone technology with meticulous historical research, petrographic analysis, and compressive strength testing. This multi-faceted approach revealed hidden problems invisible from ground level, including corroded window lintels, deteriorated concrete beams, and complex water infiltration patterns that had developed over decades. The restoration required navigating multiple regulatory frameworks simultaneously—ICRI standards, 2016 International Building Code, and City of Charleston historic preservation requirements. Professional engineers conducted extensive research into historical compliance codes and seismic requirements, ensuring the restoration met modern safety standards while preserving historical integrity. This regulatory expertise was crucial for reopening the 12th floor to guests after structural concerns had forced its closure. Perhaps most critically, professional engineering consultation provided risk mitigation that protected both the building's structural integrity and public safety. The systematic approach—from initial drone assessment through destructive testing, structural analysis, and phased restoration—prevented potential catastrophic failures while preserving a treasured historic landmark. The Francis Marion Hotel project demonstrates that complex historic restoration requires more than skilled craftsmanship; it demands the analytical rigor, technical expertise, and innovative problem-solving that only qualified engineering consultants can provide. Their involvement transformed what could have been a dangerous, code-non-compliant renovation into a model preservation project that secured the building's future for generations.

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