Track 3: For Power or For Passage: Re-envisioning Historic Industrial and Transportation Infrastructure
2 - The Stones Speak Again: Structural Renovation of the Hoen Lithograph Complex in Baltimore
Monday, September 24
10:30 AM - 12:00 PM
Hoen & Company, established in Baltimore in 1835, was the oldest continuously operating lithographer in the United States. The Hoen & Co. Complex, constructed from 1885 to 1963, is the only site that survives to represent the company’s long and illustrious history. Occupying a full city block, the earliest buildings in the complex were constructed for the Baxter Electric Co., which manufactured motors for street railways. From 1898-1902, the Bagby Furniture Company occupied the site until Hoen & Co. relocated to the building after their downtown headquarters was destroyed in a fire. Hoen & Co. occupied the property from 1902 to 1981.
The Senefelder lithographic process, invented in Germany in the late 18th century, allowed artists to draw directly on lithographic limestone from which prints could be made, eliminating the need for time-consuming engraving. Edward Weber and August Hoen brought the process to Baltimore and the company ultimately specialized in high-quality work that elevated the technique and art of lithographic printing. That the process is rooted in the artistic use of stone inspired the carving that adorns a main entrance, inscribed with the Latin phrase “Saxa Loquuntur,” translated as “The Stones Speak.” One of the many historic industrial, economic engines for the city, the abandoned architectural remnants of the complex, central to the East Baltimore neighborhood, are now envisioned as a focal point for the revitalization of this community. To do so, substantial challenges of structural stabilization and renovation had to be overcome.
Typical repairs to brick masonry and heavy timber resulting from failure of the exterior envelope were designed and implemented, including a series of masonry arch reconstructions and innovative stabilizations. However, undoubtedly the greatest challenge came from another intervention of nature. The soft, lightweight seeds of the Paulownia tree that were commonly used as a packing material by Chinese exporters in the 19th century, before the development of polystyrene packaging, sowed a mechanism of structural deterioration within the wythes of the exterior masonry walls. Paulownia tomentosa is extremely fast growing, is tolerant of pollution and can grow in a wide range of soil types. The tree can even survive wildfire, the roots quickly regenerating new stems, earning them the name of the "Phoenix tree.” This aggressive, invasive species, not unlike rusting steel expanding within a masonry substrate, can exert very large internal stresses as it sends its roots through the soft lime-mortar joints in the historic brick masonry construction. Sustained moisture in the exterior walls nourished widespread destructive growth. Undoing the damage required a combination of reconstruction and selective use of biocide.
Despite the great challenge presented, the Phoenix tree is perhaps a rich symbol for the rebirth of this new stimulus within the urban complex.
- Upon completion, participants will be able to describe lithography and its supporting industrial architecture.
- Upon completion, participants will be able to describe damage that can be incurred due to invasive trees.
- Upon completion, participants will be able to recommend treatment approach to invasive tree mitigation within masonry construction.
- Upon completion, participants will be able to describe masonry arch and heavy timber structural repair approaches.