In the late 19th century and the early 20th century when much of the buildings in the historic areas of DC were built, many alley buildings were built for industrial purposes. They worked both as carriage houses and had lofts that could be used for light manufacturing.
In a few places today we’ll still see old lucarne doors with a iron boom. Almost none are still functioning for the original purpose, today, but many decades ago they worked with a gin wheel to lift up freight or materials into the loft space. A set of lucarne doors opened up and allowed freight to be rolled in on the gin wheel. The gin wheel essentially worked like a pulley but could also roll inwards to load the material into the building.
In the pictures below you can see an example of remaining hoist booms. This particular one is built with a steel boom and a diagonal support attached to the historic common brick. The boom is installed just below an eyebrow header or segmented arch.
Another example of a historic boom is shown in the pictures below. This building is built with a stone facade. Quoin stones have been installed at the sides of the opening, below the vousoir stones at the sides of the header. The original lucarne doors have been removed and replaced with a window, at this particular location. The original lucarne doors are very interesting from a historic preservation perspective. In modern times though, many building owners prefer to remove the doors for safety. In this case a single hung window allows for increased fenestration and light into the building.
The steel booms are are better to preserve and leave in place from a historic preservation perspective. However come in in instances like this where there are steel penetrations through masonry facade there is some some small upkeep that should be applied to keep these elements in good condition. Steel and masonry experience small micro-movements overtime, at different rates, with regular daily temperature ranges and seasonal changes in moisture and temperature. Since these materials are built together, and move ever so slightly at different rates, there will be natural separation at the joint between the iron and the masonry. An elastomeric sealant should be installed at the exterior facade where the iron penetrates into the masonry.
Historically wrought iron was common, over one hundred years ago; however, today in most cases structural metal implementations would be made from steel.
In this article we talked about the following terminology and concepts, follow the links below for more related information from the IDS website:
- Carriage houses
- Lucarne doors
- Gin wheels
- Common brick
- Eyebrow headers
- Segmented arches
- Single hung windows
- Building Micro-Movements
- Daily temperature ranges
These concepts are part of the fundamentals of historic masonry restoration, tuckpointing, and brick repair.
The links in the list above will take you to other articles with more information on defects, failures, preservation and repair of historic building elements. You can learn a lot more on our blog. Feel free to check it out. If you have questions about the historic masonry of your building in Washington DC, fill out the webform below and drop us a line. We will be in touch if we can help.