Historic Stone and Patina: Signs of Living

While viewing stone on an existing building the other day, I pondered: How could we modify the terrace layout with so much of the extant stone having survived almost 200 years? How would we match the coloration, staining, chipped edges, and repairs that document the time and events since the building’s completion? The stone had a patina, for sure.

Patina 

Characteristic of all materials are the physical signs of use and change over time. Natural building materials as well as human-made things, such as bridges, farm equipment, or even silverware, develop this characteristic. Sometimes patina is due to weather, sometimes wear, or lack thereof, but materials develop and alter their appearance over an extended period.

Patina can manifest as wear marks in an original slate stair tread, showing how those that have come before travelled and placed their feet. Water-stained wood rafters and scrapes on the door casing of a barn mark the events the structure has endured. Handrails and door handles show both the dirt added and the removal of finish by the many hands that have graced their surfaces. Patina in building elements can also be viewed as damage, mistreatment, and neglect. Like wear marks, it indicates how a particular building or feature has been used over time. Some building materials are more durable than others and withstand the elements and human contact better. These significant indicators are treasured reminders of the passage of time and that nothing is truly constant.

Stone

Let’s turn back to our stone. As a material, natural stone is often thought to be long-lasting and historical. Created by enormous forces during periods when the Earth was undergoing major changes, stone took many years to form. Stone was our first structural material. Loose stones were gathered and or block stones quarried for early tombs and dwellings. Stone was later used to embellish and ornament structures, and out of it, the statues of the ancient civilizations. Throughout modern history, stone was carved, shaped, stacked, and veneered. It was so revered that when other human-made materials were developed, some to be used in place of stone, many mimicked the appearance or had the same properties of stone.

Stone is still sought today for buildings that are required to be — or want to be seen as — durable and long-lasting. Stones as hard as granite and as soft as sandstone and brownstone weather, wear, and gather dirt differently; they require different methods and techniques to quarry and tool their surfaces. How an architect chooses a particular stone for an exterior building material can be seen both as a pure design statement and a signal as to how the building is intended to last.

Sandstone and brownstone were favored building materials in the late 19th and early 20th century. Quarries in Connecticut and Western Massachusetts produced plentiful supplies, making the stones even more attractive to builders and architects; the brownstones of New York City and Boston’s Back Bay showcase this popularity. Unlike the hardy granite used previously, brownstone and sandstone were soft, easily cut and carved, and were harvested in a multitude of warm colors. Boston’s Trinity Church, designed by Henry Hobson Richardson, is an excellent example of how stone was used to give color, texture, and depth to a building.

Today, many brownstone and sandstone buildings have undergone years of weathering, atmospheric conditions, and hard use, and they’ve developed an appreciated patina. Some have endured gracefully while others have suffered terribly under the same conditions. How to repair deteriorating stone has presented as much of a challenge to architects as the decision-making around whether to repair or replace stone that has failed completely. When alterations are planned, the use of new stone is considered alongside and adjacent to existing stone.

The facilities document is the first step in a negotiation process between the lending institution and the prospective borrower. Most institutions require it to be submitted, though some also require supplemental information. Close attention is paid to the loading/unloading process and the physical path the object must take through the building to reach its display location. Some requirements, such as security procedures, may be put in place temporarily for a specific exhibition while others are deeply embedded in the design and infrastructure of the museum.

Shouldering Responsibility

Preserving our past is a responsibility that all architects must shoulder. We will keep repairing the old stone with modern methods: repairing damage with cementitious material; employing Dutchmen (cutting out a portion of the stone and replacing in kind); and fully replacing stone that is too far gone with new stone, for as long as we can obtain it. Almost inevitability, we will have to fabricate new pieces, cutting, shaping, and carving to match the shapes and sizes of those that quarried and tooled long ago. We should not shy away from making changes, but we should avoid wiping away the patina of old and experienced building elements, for that is our history, and our responsibility.