Mastering Fake Mansard Roof Installation: Part II
In today’s blog article, we’re going to look at a mansard roof that isn’t actually real. We started looking at this in last week’s blog. The picture below shows a real and historic mansard roof, but from above. It looks a bit different from above than from the ground. A ferrous metal coping has been installed above the demising wall at each side of the closest mansard roof. Ferrous metal is generally a metal alloy that includes steel or iron.
Steel is basically iron, but with more carbon. Both materials are very strong and ferrous Alloys were used extensively in sheet metal products a century ago. The metal is ductile which means that it is bendable or stretchable and can be drawn out without breaking due to brittleness, and it is very strong because steel and iron are both strong materials. Cast iron is strong in compression, meaning it can withstand heavy loads or pressure and resist bending or crushing, to a degree.
Cast iron has an even higher carbon content which contributes to its hardness and ability to resist wear. This specific type of strength makes it useful for heavy-duty applications like engine blocks, pipes, and cookware. However, unlike steel, cast iron is not ductile. Ductility, in this case, refers to the ability of a material to deform under tensile stress, such as being stretched or bent, without breaking. Steel, with a lower carbon content, has more ductility because its molecular structure allows a higher amount of movement, essentially dislocations within the material. This allows it to bend or stretch.
In contrast, cast iron’s crystalline structure, with more carbon present in the form of graphite or cementite, creates brittle bonds that break rather than bend when subjected to tensile (stretching or deforming) forces. This makes cast iron more prone to cracking or shattering under elongating tension. If you think of a blacksmith, pounding steel on an anvil with a hammer, you’ll notice that even though the steel is withstanding massive amounts of forceful impact, it doesn’t shatter. That’s an example of malleability, a type of elongating pressure.
Today, by comparison, sheet metals used for coping and flashings are more often made from aluminum because aluminum resist oxidation and deterioration better than ferrous metals. In this case, you can see significant deterioration, the entire side of the end wall coping is nearly completely covered in rust.
The next picture below shows a series of buildings alongside a street. These buildings, like many of the buildings in Washington DC are built in row, joined side-by-side. Although these buildings may look similar, the building in the middle of the photograph is a commercial building for apartments.
The buildings farther to the left are historic row homes but have also been converted into multi-unit housing buildings. Particularly for large buildings, this type of conversion is relatively common, even with historic row homes that were originally intended for just one family. As the neighborhoods changed in DC through the 20th century, the ultra wealthy chose to move out of this area and into areas that were a little more withdrawn from the center of the city.
Many historic row homes in Washington, DC were originally built for single-family use during the late 19th and early 20th centuries, aligning with the city’s residential layout at the time. Some of the larger homes were built to accommodate affluent families, often including spacious layouts, high ceilings, and multiple stories. However, as the city’s population grew and urbanization intensified in the mid-20th century, the economics changed significantly and demand for affordable housing increased. Economic pressures and changing social dynamics, such as smaller family sizes and more people moving to the city for work, led to a shift in housing needs. Demand continued to increase, but the specific type of demand changed.
In more recent decades, these large, often underutilized homes have been converted into multi-family units to address this demand. Within the past 50 years, there has been a significant change within that overall evolution. DC went through a localized economic depression, common in many cities throughout the United States between the 1980s and 2000s. Here on our blog, we’ve talked about this issue a few different times, because although the entire concept is very complicated, it does, to a degree, explain why many properties and building roofs have been severely neglected. As well, it is not necessarily a causal factor but it is related to the lack of guild-like organized trade standards in our local market.
The next picture below shows a closer view of the fake mansard roof, shown at the beginning of this series. When you look directly at the roof system here, you can see it’s not an actual roof at all. It’s just a panel system made to hide the mechanical equipment on top of the roof. The system is made with an aluminum standing seam panel. The edge of one, covering the edge of the next full stop each of these individual panels then sit inside of a framework made with a top and bottom rail and with intermediary horizontal purlins which support the individual panels.
The next picture below shows a real and actual mansard roof with a dormer. There are different styles and types of dormers, this one happens to be a flat roof dormer, as opposed to a more common gable dormer. Dormers are relatively common in mansards because unlike a typical roof, mansard roofs are actually made to be like a type of wall. They’re generally built more vertical than flat roofs, for this specific reason.
Mansard roofs originated in 17th-century France, popularized by architect François Mansart. The mansard roofs allowed architects and builders to get a bit of a tax-hack because taxes at the time in France were applied by building level, NOT by floor space. This hack essentially allowed them to sneak an extra floor into the building without having to pay tax on it. The mansard roof showed up in other architectural styles in the 19th century and during the Second Empire. Mansard roofs became common in urban architecture, even in far away places like here in the USA.
We recommend every building owner in DC who values the longevity of their roof (and their investments) and building use a contractor who values the simple and important principles of proper roof construction like Dupont Roofing DC. Learn more about our company and the proper techniques of working with roofing on historic buildings in Washington DC here on our blog at DupontRoofingDC.com, and you can call us at (202) 840-8698 and email us at dupontroofingdc@gmail.com. We are happy to help and at least talk through options.
