The historic Masonic Hall NYC underwent a multi-year, multi-phase, comprehensive masonry facade rehabilitation project.

Masonic Hall NYC

Location New York, NY

Category Cultural

Focus Area FacadesHistoric Restoration

Historic Facade Restoration

Lucy G. Moses Preservation Award

Masonic Hall NYC is a 19-story building that serves as the headquarters for the Grand Lodge of the Free and Accepted Masons of the State of New York. It is composed of two interconnected wings: the north wing, constructed between 1907 and 1909, houses the ceremonial rooms for the Masons; the south wing, constructed between 1911 and 1913, houses commercial office spaces. Both wings were designed by Harry P. Knowles (1871-1923), a Canadian-born architect who designed several Masonic buildings and was himself a Master Mason.

The north wing of Masonic Hall was designed in a highly decorated Beaux-Arts Style, while the south wing is a more restrained, but still complementary, Neo-Renaissance Style. The facades are clad primarily with ashlar limestone masonry at the lower floors, with expanses of rough textured, red clay brick walls above, inlaid with decorative maroon and beige brick.  However, the most notable exterior feature is the extensive cream-colored, glazed terra-cotta ornamentation that crowns the building, concentrated at the corners of the north wing, and the upper floors of all street facing facades.

Investigation Reveals Distress

As a building over six stories, Masonic Hall is subject to New York City’s Facade Inspection Safety Program (FISP). Hoffmann Architects + Engineers was retained to conduct a facade investigation and paid special attention to the street-facing elevations, which present an even higher level of safety concern. The investigation revealed many instances of distress and damage at all masonry facades, including cracking, spalling, displacement, open joints, and failing patch repairs within the limestone and brick masonry, and most especially within the ornamental terra cotta.

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The historic Masonic Hall NYC underwent a multi-year, multi-phase, comprehensive masonry facade rehabilitation project.

Overall view of north facade of the north wing with rehabilitated masonry (along 24th Street)

Overall view of south facade of the south wing with rehabilitated masonry (along 23rd Street)

The observed deterioration was largely related to the assembly of the building’s structure and enclosure. Although the materials used in the exterior walls express its architectural style, they also conceal its transitional construction. Unlike the masonry buildings that came before turn-of-the-century high-rises, typically constructed of load bearing walls, Masonic Hall has a steel-framed structure that carries floor loads. However, its masonry enclosure is not entirely independent from the metal skeleton. Its heavy, thick walls reinforce and fireproof the frame, and the concealed steel partially supports and anchors masonry components.

Exploratory probes performed during inspections revealed that several underlying steel components were experiencing corrosion. This caused the metal to expand, jack, and crack the adjacent masonry. In some cases, the integrity of the steel itself was also a concern.

Like many historic masonry structures, the facades of Masonic Hall contained no provisions for inevitable movement beyond its mortar joints.

Like many historic masonry structures, the facades of Masonic Hall contained no provisions for inevitable movement beyond its mortar joints. Over time, the clay brick and terra cotta expanded as water and vapor were absorbed from exposure, placing pressure within the walls that ultimately caused cracking of masonry units and adjacent mortar joints.  This expansion also caused the glazing on the terra cotta to expand from tension and develop crazing. These various openings within the enclosure enabled deeper infiltration of moisture which reached the unprotected underlying steel and caused it to corrode.

The configuration of the terra cotta also plays a role in its deterioration and associated level of safety concern. Unlike the solid brick and limestone, the terra cotta units are hollow shells. Therefore, when the units cracked, it was often through the thickness of the shell, making it more prone to becoming dislodged from its anchorage and generating loose material, especially at projecting ornamental blocks. Additionally, moisture that infiltrated through the masonry shell became trapped in the cavities of the hollow units, and as it froze, the moisture expanded during winter cycles. This resulted in freeze/thaw damage which provided yet more openings for water intrusion.

An Ambitious Facade Restoration

Addressing all this deterioration was at the core of a comprehensive masonry facade rehabilitation project. While the degree of damage on numerous units, most notably at the terra cotta, was such that they required replacement, preserving as much of the historic enclosure fabric as possible was also paramount. Therefore, a two-part strategy was implemented, replace where required by surface or substrate conditions, and repair where masonry was salvageable and service life could be extended.

One of the foremost project considerations was how to develop lasting solutions that mitigate underlying causes to deterioration and not just provide superficial corrections. This included repairing corroded steel structure exposed by masonry work. Brittle steel was scraped, reinforced with welded galvanized steel plates, and primed and painted with epoxy coatings to provide protection from moisture and further corrosion. Replacing steel components was also necessary, especially at the large terra cotta Juliet balcony. Much of the original cantilevered steel was inadequate to carry the weight of replacement blocks, so a more robust system of corrosion-resistant, galvanized steel supports and stainless-steel anchors was installed.

Typical deteriorated glazed terra cotta unit removal, surveying, and cataloging
In-progress installation of replacement terra cotta blocks, new steel anchorage and supports, steel coating, and brick
In-progress installation of replacement terra cotta blocks, new steel anchorage and supports, steel coating, and brick

After surveying and cataloging glazed terra cotta units for removal, the project team installed repaired or replacement terra cotta units, as well as new steel anchorage and supports.

Reducing moisture infiltration by closing breaches in the enclosure was also a major consideration. At the roof level, deteriorated multi-tiered terra cotta and bluestone copings along parapets were replaced with matching masonry, including copper flashings, as these sky-facing elements were a significant source of water ingress. Transverse joints were sealed with compatible caulking to further reduce infiltration and allow for movement. In many cases, heavily spalled limestone saddle joints had to be reconstructed with Dutchman inserts. Repointing of open mortar joints was performed at numerous other locations to enhance weathertightness.

Where existing damaged units could be salvaged, various repairs were performed. Cracked and spalled masonry was patched with compatible grout and repair mortar. Where cracking demonstrated the potential for loose stone or terra cotta, but the masonry was otherwise intact, the units were pinned with stainless-steel rods and epoxy adhesive. All terra cotta repairs also included mending broken glazing with breathable mineral coating to enhance moisture resistance and restore the original uniform appearance of the glaze.

Typical terra cotta and cast composite polymer resin replacement blocks, mortar repointing, and repaired terra cotta
Typical terra cotta and cast composite polymer resin replacement blocks, mortar repointing, and repaired terra cotta

Disparate elements, including terra cotta and cast composite polymer resin replacement blocks, mortar repointing, and repaired terra cotta, come together to create an integrated, secure facade assembly.

The replacement of ornamental terra cotta with substantial cracking and compromised anchorage was the most significant portion of the project, as it included hundreds of units distributed across the facades, most with a distinct shape and orientation. Terra cotta identified for replacement was thoroughly photo documented, surveyed, carefully removed, and cataloged, so the fabricators could use existing pieces to assist with replication. Sample pieces for color, texture, and profile matching, detailed shop drawings, and mock-ups were all critical steps to ensure reproduction of original configurations. Select areas of highly damaged brick and limestone were also replaced with non-corrosive steel reinforcement.

The use of substitute materials was also an important consideration. Although some steel rehabilitation was performed, much of the ornamental masonry ultimately relies on the original primary structural frame to carry loads.  Therefore, there was a concern that some cantilevered framing members have fatigued and may not be able to fully support both the replacement terra cotta and its extensive system of new steel anchorage and sub-structure within factors of safety. To address these considerations, cast composite polymer resin was used for select ornamental terra cotta blocks, as it is a more lightweight material. All other new terra cotta was replaced in-kind.

The masonry exteriors of Masonic Hall not only express the character of the building, but also speak of the history of New York construction and of the legacy of Freemasonry. The facade elements that enrich the city’s architectural landscape tell the story of terra cotta’s once great popularity and versatility, while the intricate patterns and decorations within the facades echo the organization’s rich origins. The project’s careful, thorough, and detailed efforts to address structural safety concerns and moisture infiltration issues, all while preserving historic integrity, pay homage to the legacy of the Freemasons and this New York landmark.

One of the foremost project considerations was how to develop lasting solutions that mitigate underlying causes of deterioration and not just provide superficial corrections.

Typical replacement area at facade

New York Landmarks Conservancy, Lucy G. Moses Preservation Award

Masonic Hall NYC

The New York Landmarks Conservancy’s highest honor for historic preservation, the Lucy G. Moses Award is considered the “Oscars of preservation” for New York City buildings.

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