Flat vs Pitched Roofs: A Quick Guide

Last Updated on March 29, 2022 by Kravelv

Handling roof repairs and replacements is not for the faint of heart. More importantly, it shouldn’t be performed by just anyone, especially if they don’t have the right skills, experience, and tools to complete the job. However, even if you’re going to let a professional roofer take care of your needs, this doesn’t mean you get to just sit back and ignore the process completely.

There are still some terms and procedures you should understand, and you’re going to make big decisions based on them. If you don’t know anything about your roof, you could be getting the wrong materials or the wrong estimate, and not know it at all.

 ROOF PITCH: You need to consider many factors before investing in a new roof, one of the most important of which is roof pitch.

One of the most important things you should understand is the roof pitch, or the measurement of your roof’s overall slope. It matters because it’s something that your contractor will ask you about before they accept the job. Basically, there are two general types of roof pitches: flat (or low-slope) and pitched (or steep-sloped). Understanding their features and knowing their differences will guide you better in making important roofing decisions.

All About the Roof Pitch

In a nutshell, the pitch refers to how steep your roof is. This is usually stated as a ratio, such as 3:12 (read as three and twelve), 4:12 (read as four and twelve), and so on. The first number in the pitch relates to the rise of your roof, while the second number is the run of your roof, measured both in inches. Twelve is always used for the run because it’s equivalent to one foot. So, a 7:12 roof rises towards 7 inches for every horizontal foot it travels toward your home’s center.

Knowing your roof pitch makes it easier to identify the ideal type and the amount of material to be used on your system.

So why is the roof pitch important? For starters, it helps estimate the amount of material to be ordered for the job. The steeper the slope of a roof, the more shingles it will require covering your entire system, for instance. As such, roofing shingle costs might be double on a 12:12 roof compared to one with a 6:12 pitch. This is an extremely important consideration if you’re constructing a new home. Additionally, the roof pitch helps determine the types of materials suited for your roof.

Flat vs Pitched Roofs

As mentioned earlier, roof pitches fall into two basic categories: flat and pitched.

  • Flat Roofs With pitches of 3:12 or less, they are often used on buildings, schools, and other commercial establishments due to their industrial-looking design and function. The most common types of materials used for these roofs are single-ply, built-up, and modified bitumen. Generally speaking, flat roofs are more economical to install at the time of construction compared to pitched roofs. They are also easier to walk on, especially if you’re doing inspection and maintenance tasks. Although you should always practice safety caution, whether walking on a flat or pitched roof, the former tend to offer more stability than the latter.

GREAT VERSATILITY: Due to their design, flat roofs can be turned into a number of things, including a green roof that not only beautifies a property but is also good for the environment.

Flat roofs also give property owners an opportunity to save energy and promote sustainability in their own home or building. For example, green flat roofs are becoming increasingly common among commercial buildings, as they are excellent at reducing surface temperature. The International Green Roof Association emphasized that while you can build a pitched green roof, you need to adjust the plant selection and planting methods to the slope and exposure. This can be challenging, especially if the slope is really steep. It’s possible to build a pitched green roof with a slope of 45 degrees; however, this is not the case for slopes that exceed 30 degrees. Steep-slope roofs give limited access for upkeep and maintenance, that’s why transforming them into a green one will be out of the question.

While they are functional and versatile, flat roofs do come with a few disadvantages too. One of which is their ability to carry weight. Extreme conditions, for instance, can leave your roof having to handle a generous amount of rain and snow. Compared with pitched roofs, they are more likely to collapse as a result of a severe storm, because water will have a hard time flowing downwards. The larger the flat roof is, the less stable it may become. And while a flat roof on a residential property is likely to be small enough to not cause issues, knowing that your foundation needs to make up for this structural weakness is worth paying attention to.

  • Pitched Roofs – On the other hand, pitched roofs are seen on different types of structures, but most typically on residential homes. They are generally 4:12 in pitch or higher, and often use materials such as asphalt shingles, slate, and tile. These systems offer a few benefits that flat roofs do not, the most remarkable of which against flat roofs is improved drainage capacity. It’s important to have a roof that can handle copious amounts of rain, especially if you live in an area that often experiences severe weather.

ADDITIONAL SPACE: With a pitched roof, you can take advantage of the additional space on the upper level, transforming it into a loft or attic space.

On top of the excellent drainage that pitched roofs offer, they also give you the opportunity to create more space inside your home. A pitched roof can allow you to add a loft or attic space in your interior because of their steep design. This gives you a space for your guest room, home office, or simply additional room for storage, if necessary. Not only does this extra space is advantageous in terms of functionality and convenience; it also helps boost the property value of your home.

As with flat rooms, however, pitched roofs have their own share of drawbacks. The increased cost is a good example. A pitched roof is more expensive than its flat counterpart because of the additional building materials and complex design that goes into, which also means more hours of labor during installation. They may also place more stress on a structure’s foundation than flat roofs, so reinforcing the support may be necessary, especially if heavy roofing material is used.

In sum, flat roofs are ideal for office buildings and other commercial establishments due to their stability and basic design. Pitched roofs, on the other hand, are more aesthetically pleasing and costlier, but they provide more space, which is why they are ideal for smaller structures, such as residential homes.

Ultimately, your roof’s design is up to you and your roofing contractor. When deciding between flat and pitched roofs, it’s crucial to take both the advantages and disadvantages of each into account. A professional roofing company will be able to recommend the right options for your structure, so be sure to discuss with them your plans before investing your remodeling dollars in a new roof.


Author Bio:

Danny and Zack Fix, Terry Marks, Tony Benallo formed HomeGuard Restoration in 2012. With a combined total of more than 50 years of experience, these four Colorado natives were ready to run a different kind of construction and restoration company. They put together an expert construction staff, many with over 20 years of industry experience, raising the bar on home improvement craftsmanship and customer service. Check out the company blog for updates from Danny, Zack, Terry, and Tony!


Kravelv is a full time digital marketer and part time furniture and cabinet maker. During his free time he would like to create something out of recycled woods, this varies from toys, furnitures plant boxes etc. Follow him on Twitter | Pinterest | Facebook

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