By Abbey Dolan, 2019 Intern
Each summer, Greater Portland Landmarks hires interns currently enrolled in historic preservation programs at colleges across the country to assist in our advocacy and education work. Our interns bring their knowledge of the preservation world in academia and in other parts of the country. In return, they get to live in a vibrant seaside city and gain valuable experience working in a historic preservation non-profit.
Abigail (Abbey) Dolan was raised in New Jersey and is attending the Graduate Program in Historic Preservation at the University of Pennsylvania.
What’s that crumbling? Stone flaking? Is something wrong with my building?
Front door of Safford House showing spalling loss. Photo: Abbey Dolan
A common and natural issue with stone buildings, especially brownstone, is spalling. Spalling is when small pieces of stone begin to chip away from the larger surface, usually in thin shards. If you look at any stone, brick, or even concrete constructed buildings you can sometimes see flakes that have fallen off. It's a common occurrence even in the most well-constructed building, and the age of the building doesn’t always matter.
Brownstone is particularly at risk because of the way the stone is formed. Brownstone is a porous sedimentary rock that allows water to easy flow through it via tiny holes, similar to a sponge. Brownstone is also a layered stone that is often placed on buildings sideways. Think about placing a cake on its side. You can image the layers peeling or flaking off the cake just because of gravity. The same is true for brownstone. The softness and natural coloring of brownstone made it a favorite building material for several decades. It is practically synonymous with row houses in New York City. Unfortunately, due to its tendency to break apart, it is under constant need of repair.
Of course, spalling doesn’t necessarily mean your building is falling apart. The nature of brownstone being softer and layered was known even when it was being mined, and a lot of times the visually appealing stone was just used to face a stronger building material that supported the building.
Window sill at Safford House showing spalling loss. Photo: Abbey Dolan
So, why are only some areas of your building spalling, while other areas of the same material appear fine? Generally it means there is water moving through the porous stone or that there has been a lot of exposure to salt, usually from winter road treatment. Spalling doesn’t mean your building is going to fall down, but it can be a sign of some drainage issues. This is a problem since brownstone was often used as a detail element. Lintels under windows, cornices at the roof line, and fancy carvings around the walls are often more exposed to water. Some basic maintenance can really increase the life of your brownstone and building. Gutter cleaning, fixing leaks, and keeping plants away from your building can decrease the water damage to the stone. Just don’t get carried away trying to clean or repair—sometimes harsh cleaners or repairs made with poorly-suited patches can cause more harm than good. It is best to consult experts if you have brownstone issues.
Victoria Mansion. Photo: Abbey Dolan
You might want to consider some other things about your building before you consider fixing it up. Brownstone was a historically popular building material, and there are quite a few historic buildings that have issues with spalling. Victoria Mansion is a very prominent building in Portland that has recently dealt with repairs to its brownstone. Great effort was put into acquiring stone for repairs from the original quarry the house’s stone came from. Looking at the results of the conservation efforts, there is an obvious difference in the replacement stone, which has lighter coloring than the historic brownstone. The repairs are apparent, but using the original material maintains the character.
Face Bedding vs. Natural Bedding at Victoria Mansion. In the upper half of this picture you can see the lighter replacement brownstone freshly cut and naturally bedded. Note the many swirling lines in the stone to indicate this. In the center of the photo you can see an old patch of spalled quoin which was most likely face bedded, as was typical throughout the building and which greatly increases likelihood of spalling. Photo: Abbey Dolan
Maintaining some integrity of buildings is a way to keep the building feeling whole. Since not everyone or every project has the resources to do such an elaborate reconstruction, for typical projects the best tactic is to try to minimize damage before it gets too bad. Victoria Mansion had been neglected, abandoned for almost ten years, and underfunded for even longer. Its brownstone deterioration was at an extreme level because of this, particularly on the tower and one side where extensive water damage had taken place, infiltrating the layers of stone.
This issue with brownstone can’t be avoided, but there are some things that can be resolved. If it’s on a building you own, you should be aware of the potential danger. Deterioration is inevitable, but if we want things to last we should do our best to treat them with care and consideration.
Brownstone Reference Material