What Is a Mansard Roof?
The Mansard roof is a distinctive roof style with a double slope. Learn the history of this charming roof style and its pros and cons.
The Mansard roof is a unique roofing style that first gained popularity in 17th-century France. It has a double slope on all four sides, creating a signature and easily recognizable style. While eye-catching, this may not be the best roofing type for every home. Our guide details the Mansard roof’s history and its pros and cons so you can determine if it’s the right fit for your home.
History of the Mansard Roof
Mansard roofs are easy to spot. They’re similar to gambrel roofs commonly seen on barns in America, except Mansards have a double slope on all four sides like a hip roof. The lower slope is almost vertical, while the upper slope is nearly or entirely flat.
The Mansard roof is credited to 17th century French architect Francois Mansart, but there is evidence that the roof style first appeared in Europe in the mid-16th century. Pierre Lescot incorporated the roof design in a wing of the Louvre Museum, which was built around 1550. While Francois Mansart may not have invented the roof style, he popularized it by using it in homes throughout France.
Mansard roofs soon jumped across the Atlantic, becoming popular for colonial-era homes in the Northeast. Interest in French architecture resurged in the mid-19th century, and Mansard roofs were installed on many government buildings and stately homes. You can find an example of this in the distinctive four-story Mansard roof on the Germania Life Insurance Company building on Park Avenue in New York City.
Advantages of a Mansard Roof
Mansard roofs provide several benefits—most notably architectural charm and increased space. We’ll expand on these benefits below.
Better Heat Distribution
The upper slope of the Mansard roof can absorb sunlight and send that warmth into your attic space in colder months. This design can help reduce your heating costs, especially if you live in a climate with a mild winter. The windows can bring more natural light and warmth from the sunshine if you add dormers to your Mansard roof. Opening windows in the attic can help circulate the air inside your home more efficiently.
Design Versatility
The Mansard roof’s steep slope offers more space to add personality to your home. The steep lower section is ideal for dormer windows and balconies, adding natural light and visual interest. You can choose from different styles of Mansard roofs, including convex, concave, and S-shaped, to customize your roofline’s look. The design’s versatility complements different architectural styles, from historic Victorian homes to more contemporary properties.
Increased Property Value
A Mansard roof adds plenty of curb appeal in addition to more usable living space. Homes with unique architectural designs like Mansard roofs stand out in a neighborhood, making them more attractive to potential buyers. This factor can increase your home’s resale value.
Maximized Living Space
The steeper lower slope of the roof creates more headroom in the attic, adding another floor of interior space to the home without increasing the footprint of the building. This is why you’ll find Mansard roofs in many urban areas, where there’s often limited space to expand a home outward. Homeowners can use the Mansard roof to build up and get more square footage.
Disadvantages of a Mansard Roof
As with any roofing option, a Mansarf roof has a few cons. Here are some of the drawbacks.
Building Regulations
Some building codes limit the use of Mansard roofs, sometimes because of historical preservation. Check with your local building department to ensure there are no restrictions on Mansard roofs in your area.
Cost
The Mansard roof’s design is complex. Installation is labor-intensive and requires more materials than a traditional roof design, such as a gable roof. You can help lower your roofing costs by keeping the design simple and opting for less expensive materials, such as asphalt shingles.
Increased Maintenance
A Mansard roof’s steep angles can make maintenance more difficult. You can’t stand on the lower slope, so you must be on a ladder or hanging over the upper slope to complete repairs or inspect your shingles. This also makes replacing a Mansard roof more complicated and costly than other roof types. These limitations can increase your risk of injury and make it difficult to spot issues with your roof. We recommend scheduling regular inspections with a professional roofer if you have a Mansard roof.
Water Pooling
A mansard roof’s upper slope is relatively flat, so it’s not very good at shedding water from rain and snow. Pooling water and snow accumulation could cause structural damage. A Mansard roof may not be a good choice for homes in areas that get a lot of moisture, but an architect may be able to alter the roof’s pitch to help with water accumulation.
Design Variations of Mansard Roofs
The Mansard is easy to recognize, but there are several variations that can make its aesthetic even more unique.
Concave Mansard Roof
The concave Mansard roof, also known as a French curve Mansard roof, is very complex and requires specialized experience to install. The lower, steeper slope of the roof curves inward slightly, creating a gentle scoop in the roofline. You might see this variation in historic homes, especially in Paris.
Convex Mansard Roof
A convex Mansard roof has a lower slope that gently curves out, creating a bell shape. This design is the opposite of the concave version. Convex styles have become popular in government buildings, and they are great for maximizing attic space. However, they don’t offer good drainage, so they’re best for drier climates.
S-Shape Mansard Roof
The S-shape, or serpentine, Mansard roof forms the shape of the letter S by first curving inward before reversing direction and curving out at the top. This is a highly complex roof design with visual interest, but it will cost more upfront and require more maintenance.
Straight Mansard Roof
The straight Mansard roof is a more classic version of the original design. Its straight upper slope meets the lower slope at a sharp angle. You may see this Mansard roof style in Victorian homes, but it’s suitable for many architectural styles.
Roofing Materials
Builders and homeowners must carefully consider what roofing materials are suitable for a Mansard roof. Due to their unique design, Mansard roofs can strain the home’s structure, so it’s best to stick with lightweight roofing materials.
For example, asphalt shingles are heavier than metal and might not work well on the roof’s steep slope. Synthetic shingles and a metal roof are lighter and more durable. These will also offer better weather resistance—an important consideration for a Mansard roof that could be prone to water pooling.
The topmost portion of the Mansard roof may be almost flat or completely flat. A flat roof will need a membrane roof system to protect the interior structure from pooling water. White membrane roofs are ideal for homes and commercial buildings in warmer climates, as they reflect heat and help keep the interior cooler.
Our Conclusion
The Mansard roof is a distinctive roof style with double slopes on all sides. It has aesthetic appeal but also offers practical benefits, such as adding extra space to an attic and creating opportunities for more natural light with dormer windows. First popularized in Europe, the classic French roof is now found worldwide.
A Mansard roof’s complex design makes it expensive to install and maintain compared to simpler roof styles, such as a gable roof. It may not be suitable for homes in climates that experience heavy snow or rain, as the roof design doesn’t offer good drainage.
If you love a property with a unique look and want to maximize your living space, a Mansard roof can be the perfect crowning touch for your home.
FAQ About Mansard Roofs
What is the purpose of a mansard roof?
The purpose of a Mansard roof is to maximize attic space. The roof’s steep slope creates more living space inside the attic and allows you to add dormer windows and balconies to bring in more natural light.
What does a mansard roof look like?
A Mansard roof has two slopes: a lower slope that’s steeply pitched to create more attic space and an upper slope that’s nearly flat on top. It’s similar to a gambrel roof, often found on American barns, but slopes down on all sides and has no gables.
What are three disadvantages of a mansard roof?
While aesthetically appealing, the Mansard roof has several disadvantages. Its complex design means it’s more expensive to install. It’s also harder to maintain, as you can’t stand on the roof for inspections or repairs. It’s unsuitable for climates that experience high amounts of rain and snow, as the low slope of the upper roof isn’t ideal for shedding water.
What is the difference between a gambrel and a mansard roof?
The difference between a gambrel and a Mansard roof is that where a Mansard roof slopes down on all sides, a gambrel roof only slopes down on two sides.
Is a mansard roof flat on top?
A mansard roof may be flat on top or have a very low slope. Some styles may slightly increase the top’s slope to prevent water pooling.
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