What is a Mansard Roof? (French or Curb Roof)

Have you seen homes that have shingles on the roof and the sides? Do you have one yourself? If so, this kind of roof is called a mansard roof (aka French or Curb roof).
But what exactly is a mansard roof? Luckily, we’re here to help out.
The team at Bill Ragan Roofing has provided high-quality roofing services to the residents of Nashville since 1990. Our workmanship ensures you get the most out of your roof. That’s why we offer a lifetime warranty.
So, what is a mansard roof? Always eager to educate anyone on the art of roofing, I’m going to break it down for you.
By the end of this article, you'll know what a mansard roof is and 3 things you need to know about them. And after you get done reading, we're going to help you find a great roofing contractor for your mansard roof.
What is a mansard roof?
A mansard roof (aka French or curb roof) gives your home a Tudor or a Cottage look. The look of this roof isn’t like the common ones you’ll see in your neighborhood.
So, what exactly is a mansard roof? A mansard roof isn’t just the roof, it’s actually the outer walls of your home as well. This means the top story of your home will have the roof (shingles) all the way around instead of just at the top.
The roof isn’t exactly vertical, but it’s as close as you can get. It will come out about 2 feet from the bottom then slant up to the ridge so that there’s still enough of an angle for water to run off into the gutters.
A mansard roof has an interesting look, but it still serves the same function as other roofs.
3 things to know about a mansard roof
You just learned what a mansard roof is. But there are still a few important things you need to know about it.
Continue reading to learn 3 things to know about mansard roofs.
1. A mansard roof has the steepest pitch a roof can have
Remember, a mansard roof isn’t vertical, but it’s as close as it gets. This makes a mansard roof the steepest pitch a roof can have.
But what is roof pitch? Roof pitch is simply the angle (steepness) of your roof.
Your roof’s pitch will be a ratio that is calculated by the number of inches or feet it rises vertically for every 12 inches or feet it extends horizontally. For example, a roof that has a 6/12 pitch will be 6 inches (or feet) up for every 12 inches (feet) out.
Because of its steepness, a mansard roof is the exact opposite of a low slope roof. However, they do have something in common. They both aren’t the right fit for the commonly used asphalt shingles.
To learn more about how a low slope roof compares to a mansard roof, read this article on what a low slope roof is (& what roof system is right for it).
2. I don’t recommend asphalt shingles for a mansard roof
Remember, asphalt shingles aren’t exactly the right fit for a mansard roof. But why?
Installing shingles on a mansard roof is like hammering shingles to a wall. The weight of asphalt shingles are too heavy to hang at the pitch of a mansard roof.
Because of this, it’s almost impossible to stop the asphalt shingles from sliding down the vertical sides of a mansard roof. Even when following the manufacturer’s installation instructions, asphalt shingles will eventually start sliding off.
Your roofing contractor can do everything possible to keep this happening, like using 12 nails and using drops of sealer, but even this won’t stop the shingles from coming down.
Be aware, just because they aren’t the right fit doesn't mean they can’t be installed on your mansard roof. However, if you have this kind of roof, I wouldn’t recommend asphalt shingles.
3. What are the right types of shingles for a mansard roof?
You just learned why I don’t recommend asphalt shingles for a mansard roof. So, you’re probably wondering what shingles are the right fit.
There are two options I recommend for a mansard roof, synthetic shingles and cedar shake shingles. Synthetic shingles are made out of recycled plastic to look like slate or cedar shake shingles.
They're a premium line of shingles, so they’ll be more expensive than standard asphalt shingles. However, they won’t slide off the vertical sides of a mansard roof.
The other type of shingles are cedar shakes. Cedar shake shingles are a premium shingle made of natural wood (cedar) materials.
Instead of hammering every individual cedar shake shingle to the vertical sides of the roof, they make a strip of 6 cedar shakes to install as panels. The panels give the look that each shingle was installed individually.
Like the synthetic shingles, they’ll be more expensive than asphalt shingles. Ultimately, it’ll be up to your budget and the look you want when deciding what shingle to put on your mansard roof.
Ready to hire a contractor to take care of your mansard roof?
Now you know what a mansard roof is and 3 important things to know about them.
Remember, you can get asphalt shingles for your mansard roof but I wouldn’t recommend it. I recommend synthetic shingles or cedar shake shingles.
After reading this, are you ready to replace or maintain your mansard roof? If so, it’s crucial to hire a great local roofing contractor.
But how do you find one? That all boils down to asking the right questions and getting the right answers back. Luckily, we have these questions and answers all ready for you.
The team at Bill Ragan Roofing has been replacing roofs (including mansard roofs) in the Nashville area since 1990. We know what it takes to maximize the life of your roof. If you’re local to Nashville, don’t hesitate to contact us to take care of your mansard roof.
Whether you're local to Nashville or not, check out this article on the Top 8 Questions to Ask a Roofing Contractor to help you spot a great roofing contractor out of all the options in your area.