When you are selecting a design for your new home or commercial structure, one of the first things you’ll need to decide is whether you want a pitched roof or a flat roof. Most people wonder, is one better than the other?

Sometimes, living in an HOA community may mean you must choose one type over another. Also, the local weather climate may mean you want to choose pitched over flat. 

The truth is that both have their pros and cons, and the best choice is really up to you. The crucial thing is that either type is properly engineered, installed and maintained. As long as that’s the case, both can be a great choice for any structure. 

Both styles of roofing have a variety of coverings available, such as shingles or membranes. With all of the modern color and texture choices, you’re sure to be able to find something that fits the look you are going for as well as your budget.

Roof Slope

When we talk about pitched or flat roofs, we’re referring to the “slope” of the roof, or how steep it is. Roof slopes are measured by how much it goes down in 12 inches. So, if a roof goes downward by 1 inch, it’s called a “1 and 12.” That would be a very flat roof. On the other hand, a roof that goes down 10 inches, a “10 and 12” would be a very steep roof.

When a roof is sloped at 3 and 12 or less, it’s called a “flat” roof or “low slope” roof. Remember that no roof is truly “flat.” All roofs need to have some slope to them to allow water to drain. Roofs that start at 4 and 12 slope and greater are called “Pitched roofs.”

Flat roof advantages #1: lower cost

One of the biggest advantages of flat roofs is that they are generally cheaper to install. Pitched roofs require more lumber or supporting trusses to achieve the sloped shape. 

The membranes or other roofing materials that make up the outer shell of flat roofs are often less expensive than shingles or concrete and clay tiles.

Flat roof advantage #2: space efficiency

Another advantage is in space efficiency. This is mainly a concern in commercial or office buildings. The top floor of a flat roofed building can have more usable space. When a building has a pitched roof, the top floor can be very small and difficult to use.

This isn’t such a problem on residential homes which often use the smaller space for storage or a bonus room. In larger commercial buildings, a high pitched roof may mean that elevators or staircases don’t match up to the top floors, which makes accessing them inconvenient.

It’s possible that with the right design, a flat roof can even be turned into usable outdoor space, for a garden or patio. When it comes time to do that roof inspection, walking around on a low pitched roof is much easier and less dangerous than it is on a steep roof.

Flat roof advantage #3: style

Style is a huge reason people choose flat roofs. They have a very modern and clean look. Most modern office buildings and skyscrapers have a rectangular shape of various proportions, and a flat roof completes that look. 

Mid century homes often featured low slope or flat roofs, and when people design homes to fit with this aesthetic, they’ll often choose something similar. 

Flat roof disadvantages:

The lower slope of a flat roof means that water will not cascade off as quickly as it would on a pitched roof. If there are any imperfections in the design, it’s pretty easy for water to pool in certain areas which can mean real trouble. 

Anywhere that moisture builds up, it can eventually find its way inside. Additionally, areas that remain wet can be a breeding ground for mold and moss growth, which leads to additional problems. Leaves, twigs and other debris can also build up, and that means you or a qualified roofer will have to climb up to clear it. 

Live in an area with snow and ice? This can be a real problem with flat roofs, as the weight of the snow can lead to structural problems, and in extreme cases, even collapse. Anyone choosing a flat roof in a winter area needs to make sure it’s engineered to handle the load.

Pitched roof advantage #1: classic look

For houses, the look of the pitched roof dates back centuries. It’s truly the classic style, seen in storybooks, paintings and pictures. In most neighborhoods, it’s exactly what fits the look of the other homes in the community.

Pitched roof advantage #2: water drainage

The steep slope of a pitched roof means that water will just cascade down off the roof into the gutters, meaning much less risk of moisture build up.

It also means that leaves, snow, branches and other debris is much more likely to blow and fall off, keeping the area clean and clear. Keeping those gutters clear is crucial to making sure the roof pitch can do its job!

Pitched roof advantage #3: material choice

Flat roofs can’t use shingles as a roofing material. This is because the way shingles are laid on top of one another requires gravity to make sure water doesn’t creep between the layers. For pitched roofs, you have a wide range of choices in shingles, clay tiles, concrete tiles or wood shakes.

Many people don’t like the look of the artificial membrane, gravel or tar found on a flat roof. Shingles, shakes and tiles all have a classic look that can fit nearly anyone’s style.

Pitched roof disadvantages:

Depending on the exact shape of your pitched roof, it can cost more to install. Sometimes more complex engineering is required to form dormers and other peaks and valleys to the roof. This means more building materials and more labor.

Another disadvantage is that the valleys of pitched roofs can be areas especially vulnerable to water intrusion. It’s really important to keep these areas free of debris, and inspect them periodically.

Finally, pitched roofs are more difficult and hazardous to maintain. The steeper the pitch, the more it’s recommended that you hire a qualified roofer like Horizon to perform any inspections and maintenance. Professionals use the proper safety equipment and techniques to stay safe while fixing roofs.

Pitched vs. Flat: Which one is better?

With a variety of pros and cons of each, it’s up to you to decide which choice best fits your style and budget. As long as either type is installed correctly and maintained, they can last for decades!

Sources:

https://www.newenglandmetalroof.com/flat-vs-pitched-roof/

https://www.redfin.com/blog/pitched-roof-vs-flat-roof-whats-the-difference/

https://wernerroofing.com/blog/pitched-roof-vs-flat-roof-pros-cons-of-each/

https://www.exteriorproinc.com/blog/snow-and-ice-on-a-flat-roof