A mansard roof is one of the more unique styles of roofs, especially in a residential setting. Beyond its aesthetic, it offers a set of benefits that other roofs can't match—however, it also comes with some special considerations. On the right home, mansard roofs can provide both style and protection for you and your family.
What Is a Mansard Roof?
First gaining popularity during the French Renaissance before expanding to other countries, mansard roofs traditionally have four sides: each side has two slopes, one above the other. The lower slope has a much steeper pitch than the upper slope.
Mansard roofs can be part of a gambrel design but do not have to be. They can tie into a low-slope roof or be the visible side of a parapet on a low-slope roof in both residential and commercial construction. The main difference is that mansard roofs on residential houses have four sides, while gambrel roofs only have two. Hip roofs and mansard roofs also share similarities—they both have four sloped sides—but the mansard's dual slopes draw a distinction.
What's the History of Mansard Roofs?
Mansard roofs became popular in France during the 17th century, but their creation dates back to the 16th century. The architect François Mansart used their design to help increase the living space in his buildings. This French foundation is why the style is commonly called the "French roof."
In the 19th century, architects in the United States started to use mansard roofs in their design, which grew their familiarity. The ability to add more living space upward without needing to expand sideways made this style quite an attractive option, especially in urban areas where land was scarce.
In recent years, the roof has decreased in usage due to height restrictions in some areas. Mansard roofs are much more common in large buildings rather than single-family homes. However, there are still plenty of large family homes throughout the nation that use mansard roof designs due to their unique ability to add living space to the home.
What Are the Benefits of a Mansard Roof?
The benefits of mansard roofs include aesthetic value, added space, compatibility with dormer windows, and improved heat and light distribution.
Elegant Design
Aesthetics played a significant role in this roof spreading beyond France. Mansard roofs offer an elegant look with their two-slope structure that can be difficult to match with styles like flat or gable roofs. The design also allows and encourages the use of multiple windows on the lower slope, which gives it a stylish appearance from the outside.
More Usable Space
Due to their design, mansard roofs allow for significantly more usable attic space. Without a steep roof pitch cutting off space, as with a gable or hip roof, you can make an additional room out of your attic.
Another favorable feature is ease of expandability. If you're looking to add more space to your home one day, a mansard roof's near-vertical bottom slope can make this process much easier.
Ideal for Dormer Windows
Mansard roofs are the ideal roofing system if you plan to install dormer windows. Dormer windows allow more natural light and fresh air to enter your home, which can bring life to any space and make it appear larger.
Dormer windows can also help transform a dark attic into a more cozy living area, which is why these windows are consistently used with modern mansard roofs. The steep design of the mansard roof's lower slope allows dormer windows to fit perfectly into this space and create a cohesive look.
Improved Heat and Light Distribution
The added space that mansard roofs provide allows for additional insulation, which can improve the overall heat distribution and energy efficiency of your home. The superb ventilation and light distribution capabilities associated with these roofs can help keep dark, humid areas, like your attic, feel more homey. When combined with dormer windows, more natural sunlight can brighten up the area and allow for better air circulation.
What Are the Types of Mansard Roofs?
There are four main mansard variations, each of which can affect the look of the roof.
- Straight: A straight design has a minor top slope that isn't always visible and an almost vertical (straight) bottom slope. If you look at it from the bottom, it's hard to see the slope at the top.
- Convex: A convex design is similar to a straight design, but the bottom slope curves outward. You can get the most space out of the area with this option.
- Concave: A concave design curves inward at the bottom slope. While this can appear quite elegant, it reduces the amount of indoor space compared to straight and convex variations.
- S-shaped: An s-shaped design combines concave and convex styles. It begins with an inward curve at the top, transitioning to an outward curve in the middle. This creates a unique appearance that reduces the amount of space at the top half but makes up for it at the bottom half.
Which Materials Are Used for Mansard Roofs?
Certain roofing materials work best for this type of roof due to its unique characteristics, including synthetic shingles and cedar shake singles. Asphalt shingles can also work on mansard roofs, and their lightweight build puts less stress on the roofing structure than heavier materials. However, because mansard roofs are vulnerable to extreme weather conditions, it's important to use high-quality asphalt shingles.
Synthetic shingles are formulated to be resistant to fire, moisture, and heavy impacts. Synthetic shingles are made of materials like plastic and rubber, which won't absorb water. In roofing environments where standing water is a problem, they work superbly. Synthetic shingles have a higher initial cost than traditional asphalt shingles, but their increased durability and fewer maintenance requirements can lead to long-term cost savings.
Often pricier than both asphalt and synthetic shingles, cedar shake shingles offer a rustic beauty and traditional appearance. These shingles are resistant to sharp winds and hold up well against rain and snow storms as long as they're properly sealed. You'll just need to keep up with their maintenance to ensure they're always protected against the elements.
Are Mansard Roofs More Expensive?
The elegant appearance of mansard roofs does come at a significant cost. While their construction allows for more usable space, these roofs might require more permits if the building structure changes or if zoning codes are affected by the additional living space. Their complex design also creates a unique set of installation challenges, making it a longer process that tends to use up more material. This often means higher labor and material costs.
Mansard roofs don't offer the most ideal weather resistance, since the low slope at the top means that snow, debris, and rainwater don't drain easily. As water builds up and seeps into your roofing materials, it can lead to rot and mold, so routine maintenance is key to keeping the roof in good condition.
Mansard roofs can be an excellent option, providing extra attic space and an elegant, classic aesthetic, particularly in areas with moderate weather. If a mansard roof sounds like a good option for your home, contact a GAF-certified roofing contractor* for your next roofing project.
*Contractors enrolled in GAF certification programs are not employees or agents of GAF, and GAF does not control or otherwise supervise these independent businesses. Contractors may have agreed that they will use GAF roofing products, and may receive benefits, such as loyalty rewards points and discounts on marketing tools from GAF for participating in the program.
